What does an apostrophe mean in English? An apostrophe in English is a comma that changes the essence of a sentence.

What's kickin', everyone?! Today we continue to brutally eliminate doubts and add confidence to your knowledge regarding the English apostrophe: we will go over the basic rules for its placement in English, talk about the apostrophe in possessive nouns, in singular and plural nouns, in compound nouns, in numbers, etc. when it should not be used. Let us (let's) get to it!

If you put it that way, the apostrophe may be the most overused punctuation mark in the English language. It's funny, but if you throw glance on US street signs, advertisements and store windows in some city areas, you may get the impression that not everyone understands how to use it correctly. It"s not an apostrophe - it"s a catastrophe!

What is an apostrophe in English?

Apostrophe- This superscript as a comma (").

Oh, this... insidious "comma on top"! It can sometimes become a big problem for English learners. Sometimes it becomes so difficult to immediately understand which side of the word to put it on. Let's find out!

The apostrophe performs only 2 functions:

  • Indicates an abbreviation (letters or numbers).
  • Shows affiliation.

Using an apostrophe to indicate ownership

  • Put an apostrophe before « s"when something (someone) belongs to someone (something) and the owner is indicated in singular.
a baby's toy;
Hannah's kitten;
a child's cry;
girl's doll;
boy's balls.

It doesn’t matter how many things the owner has (there is only one doll, but there are many balls). The only important thing is that the owner is indicated in the singular - a girl and a boy.

  • And if there are already several owners (or something), then an apostrophe is placed after « s».
We'll take mine parents" car for a ride! - Let's go take my ancestors' car for a ride.
Your grandparents are yours parents" parents. Wow! - Your grandparents are your parents’ parents. Wow!
We're fighting for workers" rights. - We fight for workers' rights.
It's a ladies" fashion dream. - This is the dream of every fashionista.

Of course, there are also such atypical nouns, the plural of which is formed in a different way. In such cases, the apostrophe is placed in the same place as in the case of singular nouns, since such words do not end in “s”:

children's toys(toys for children);
women's magazine(magazine for women);
men's work(men's work);
people's lives(people's lives);
fish's tails(fish tails);
sheep's heads(sheep heads).

By the way, remember that “aircraft” in the plural will remain “aircraft”?

  • We put between two« s" after singular names ending in "s".

In general there are 2 options here:

Charles" or Charles's book;
the octopus" tentacles or the octopus"s tentacles.

Both options are grammatically correct. However, based on the rules, the second one will be more correct, given that the noun “Charles” is singular. But the first one is easier :)

  • Also, an apostrophe + “s” is used when the sentence talks about joint ownership of something. In this case, it is placed after the last name.
The man and woman's car was badly damaged. - The car of the man and woman was badly damaged.
We like Jade and Simon's new products. - We love Jade and Simon's new products (meaning that the new products were jointly invented by Jade and Simon).

And if it were " Jade's and Simon's new products”, then this would mean that they made/released completely different new products and not at all together.

The student's and the teacher's ideas were in conflict. - The ideas of the student and the teacher contradicted each other.
  • If a compound noun belongs to another noun, add an apostrophe only to its last element.
My sister-in-law's love of shopping knows no limits. - My daughter-in-law’s passion for shopping knows no bounds.
The president-elect"s agenda proposed no major policy changes. - The new president's action program does not imply major policy shifts.
  • If a noun belongs to an indefinite pronoun, then it also is added apostrophe + "s".
Does anybody's key fit this lock? - Does anyone have a key to this lock?
Someone's car is parked in the loading zone. - Someone's car is parked in the loading zone.

  • Apostrophe + "s" is added at the end of certain professions or positions to designate a place of work.
She"s on her way to the doctor's. - She's already on her way to the doctor.
He's at the hairdresser's. - He's at the hairdresser.
I'm gonna hit the butcher's on my way back. - I'll drop by the butcher shop on the way back.

The following examples of the use of apostrophe will also be interesting:

The text must go to the printer's(text must go to print).
Rates are lower than others companies"(rates are lower than other companies.

The apostrophe is placed here because the sentences refer to “the printer’s company” and “other companies’ rates” (the words “company” and “rates” are simply omitted).

  • If the name in front of you is classical Greek, or if it is historical figure or building, then an apostrophe is added only in special cases.

For example:

Dickens novels
St Giles Cathedral
Jesus" nativity
Moses" parting
Sophocles plays
  • Apostrophe + "s" always used, when it comes to time periods.

For example, “one month"s holiday" (one month long holiday), "four hours" delay" (four hour delay).

Just remember that holidays refer to months (singular) and delays refer to hours (plural).

Using an apostrophe to shorten

So, the second function of the apostrophe is to replace letters or numbers in a word.

The use of the apostrophe in this function can be divided into several categories.

  • Spoken English:

I"m= I am - I"m coming( am);
we're / they're= we are / they are - They"re joking ( are);
he's / she"s / it's= he is / she is / it is - It's growing ( is);
she"s / he's / it's = she has/he has/it has - He's got it ( has);
they"ve / we"ve= they have / we have - We"ve got smth to tell you (have);
had/would = "d;
shall/will = "ll;
not = n"t.

Don't(do not) forget to vote! - Don't forget to vote!
I"m(I am) so sick of this cold weather! - I'm so sick of this cold weather!
They"ve(they have) gone too far. - They've gone too far.
You'd(you had) better do that. - You'd better do it.
I"d(I would) do that for you. - I would do it for you.
I"ll be(I will/shall) there for you. - I'll be there for you.

Well, don’t forget about “ and»: « rock"n"roll», « salt"n"pepper».

  • Special abbreviations

There is such a phrase as “ p"s and q"s" = "please" and "thank you" = manners or "your own business", your own life.

In this case, the apostrophe is used to form the plural form of individual lowercase letters. All this is done to make it easier to read nouns and plural numbers.

Women curtsied and minded them p"s and q"s. - Women curtsied and did not poke their nose into other people's affairs.
His 2"s look a bit like 7"s. - His twos look a little like sevens.
She got straight A"s in her exams. - She got straight A's in her exams.

  • When it comes to years and decades.
French students rioted in "68 (1968). - French students rioted in '68.
He worked as a school teacher during the "60s(1960s) and early "90s(1990s). - In the sixties and early nineties he worked as a teacher.
  • In memory of an older version of the word

The apostrophe also indicates that original, from which the word came, once upon a time was longer, but over time it was simplified:

"cello- violoncello;
o"clock- shortened form of grammatical construction 18th century of the clock.

In literature, the apostrophe is often used to express some local dialect, for example, the speech of a typical Londoner.

«" ave you seen "em "Angin" around" ere lately?" = " Have you seen them hanging around here lately?" -Have you noticed them hanging around here lately?

Although reductions are quite common in English and make your speech more natural and comfortable, they are best avoided in official documentation.

When not to use an apostrophe

The most common mistake is adding an apostrophe where it is not needed. We found apostrophes in the most amazing places... Below are pertinent tips to avoid confusion.

  • Do not use an apostrophe in possessive pronouns: " whose», « ours», « yours», « his», « hers», « its" or " theirs».
  • Do not use an apostrophe in plural nouns that are not possessive: " CDs», « 1000s" or " 1960s».

  • Don't use an apostrophe in verbs. Sometimes it is declared in those ending in “s”: “ marks», « s ees", "finds".
  • Sometimes people get confused reduction « it is» ( it's) and the possessive pronoun " its" It's not the same thing at all. Compare.
The dog pulled on its leash. - The dog pulled mine leash.
I just realized it's time to go! - I just realized - it's time to go!

  • Also sometimes people confuse the possessive pronoun “ your" and abbreviation " you are» ( you're).
Don't forget your umbrella - Do not forget mine umbrella.
You"re the worst dancer I"ve ever seen. - You worst dancer I've ever seen.

  • And besides, there is also " whose"(whose, "whose, "whose) and " who's"(who is). Same scenario as above.
Whose turn is it to take out the trash? - Whose turn to take out the trash?
I wonder who's going to play Hamlet. - Interesting, Who going to play Hamlet?

Conclusion

When in doubt about whether to use an apostrophe, think about the meaning of the word (or words).

Think about whether this noun belongs to something? Is the word divided into two separate ones in this abbreviation? This can help;)

Big and friendly EnglishDom family

There are several in English distinctive features. One of them is the apostrophe. This small sign sometimes becomes a big problem for students, as many people confuse when to put an apostrophe and when not to.

Today we will understand its use once and for all. In the article you will learn:

  • using an apostrophe to indicate ownership

What is an apostrophe in English?

Apostrophe is a superscript comma (").

Although we don't use this sign in Russian, I think you've probably seen it. Many foreign names are abbreviated with an apostrophe. For example: d'Artognan instead of de Artognan.

The apostrophe in English is used in 2 cases that can be easily remembered:

1. To show ownership

2. To indicate a gap when abbreviating words

Let's look at each of these use cases in detail.

Using an apostrophe to indicate ownership


We use an apostrophe to show the identity of an object/person. To do this we just need to add "s to the word that names the owner.

To test ourselves, we can ask questions to such a word: whose?, whose?, whose?, whose?. For example: (whose?) Tom’s computer, (whose?) sister’s dress, (whose?) dog’s ball.

Examples of using apostrophe:

Give me Ann 's copybook.
Give me Anna's notebook.

This is my parent "s car.
This is my parents' car.

I took my friend 's phone.
I took a friend's phone.

Books lie on teacher s desk.
The books are on the teacher's desk.

Hey his sister 's cookies.
He ate his sister's cookies.

When else is an apostrophe used in English?

There are also several nuances to this rule that you need to remember:

1. Owners are multiple people/animals.

In this case, to the word that denotes them (it will be plural), we simply add an apostrophe (") without the letter s . After all, we have already added the ending -s to such words to form plural form(cat - cats - cats", girl - girls - girls", sister - sisters - sisters", friend - friends - friends").

However, if the word is not formed according to the rules (you can read about such exceptions), then we add "s:

2. Two owners

For example: mother and father, Tom and Peter, Mary and Jane.

There are two options for adding an apostrophe here.

  • One item belongs to two people

We add "s to the last word: mother and father"s, Tom and Peter"s, Mary and Jane"s

Mother and father "s car stays in garage.
Mom and dad's car is in the garage. (We are talking about one car that belongs to two people)

Tom and Mary "s house is big.
Tom and Mary's house is big. (We are talking about the same house owned by both Tom and Mary)

  • Each owner has his own item that belongs to him

We add "s to each word: mother"s and father"s, Tom"s and Peter"s, Mary"s and Jane"s

Mother "s and father "s cars stay in garage.
Mom and dad's cars are in the garage. (We are talking about two cars: one belongs to mom, the other to dad)

Tom 's and Mary "s houses are big.
Tom and Mary's houses are large. (We are talking about two different houses that have different owners)

Apostrophe with possessive pronouns in English

We don't add "s to possessive pronouns (her/hers, your/yours, their/theirs), despite the fact that they answer the questions: whose?, whose?, whose?.

Incorrect: She lost her "s pen.
Correct: She lost her pen.

Using an apostrophe to shorten English words


In English we can abbreviate some words. In such cases, we put an apostrophe (") in place of missing letters.

Here are the main accepted abbreviations:

I am = I"m
You are = you're
He is = he's
I have = I've
I would = I'd
I will = I'll
not = n't

Examples:

He's studying now.
He is studying now.

We're ready.
We are ready.

I"m calling him.
I call him.

They can't leave.
They can't leave.

I'll translate.
I will translate.

So, an apostrophe is a sign in the form of a superscript comma ("). It is used to show ownership or for abbreviation. Now let's practice using it in practice.

Reinforcement task

Translate the following sentences into English:

1. This is my friends' wedding.
2. Take Tom's car.
3. This is my dog's ball.
4. We will live in her parents' house.
5. Bring Kate and Peter's laptops.
6. He ate Dasha's apple.
7. Peter's friends will arrive tomorrow.
8. John and Mary's phones are on the table.

Leave your answers in the comments below the article.

English is a storehouse of exceptions, special occasions and sustainable structures. People just starting to study it, of course, are scared off by the peculiar rules, and even more so by the exceptions to them, but these difficulties arise only at first. As they master English grammar, students come to understand the simplicity and logic of this foreign language. And what was difficult at first glance becomes immediately clear and obvious at second glance. Let’s see this in practice by examining today’s topic: the ending s in verbs in English, as well as the use of endings in nouns and adjectives.

Russian speech is a synthetic language, that is, to create the correct context, we inflect words, add prefixes and suffixes to them, and also change places of any members of the sentence. English, on the contrary, is a characteristic representative of the group analytical languages. In his system, the main emphasis is placed on a strictly fixed order of sentence members, and additional expression of connections is carried out using service and auxiliary words. To put it simply, in such speech the relationships between words are conveyed not by the endings of these words, but by their place in the sentence and proximity to prepositions.

  • Beautiful cat A sitting at the door -Abeautifulcat issittingatthedoor (word order – subject).
  • I see a beautiful cat atIseeabeautifulcat(word order – addition).
  • I'm going to a beautiful cat e . – Igoto abeautifulcat(preposition of direction + object).

As can be seen from the examples, the English manage perfectly well without a system of declensions of words. But grammatical category endings still exist in their language, and have as many as three representatives. We will find out what they look like and what their purpose is in the following sections.

The ending s for verbs in English

The most common case of using an additional letter at the end of words is when the verb is placed in the 3rd person singular simple present tense. It includes the pronouns he, she, it (he, she, it) and nouns that can be replaced by these pronouns. Recall that it denotes only inanimate objects, which in English can also include animals (if they are not pets).

Simple describes regular, everyday, habitual actions, so it can often be found in English speech. Accordingly, incorrect placement of the predicate in the third person is a very serious mistake that will hurt the ears of a foreign interlocutor. In order not to blush for your English, you need to remember a simple rule.

Let's consider the use of this law in practice.

  • Shewatch es manyTV-showseveryday – She watches a lot of television shows every day.
  • It sound s very strange – This issoundsVeryWeird.
  • He eats chip s and drink s lemonade – HeeatingchipsAnddrinkslemonade.

For the third person, the verb ending is also retained in the negative and interrogative form, undergoing a slight change to - es, and being added not to the main, but to the auxiliary verb. In this case, the main predicate is in the form of a simple infinitive.

  • Do es Jessica write a letter to him? – She do es n't write a letter to him.
  • Is Jessica writing him a letter? – She doesn’t write him a letter.
  • Do es a koala become a big and strong animal? – It does es n’t become a big and strong animal.
  • Is the koala becoming a big and strong animal? – She does not become a big and strong animal.
  • Do es your father work as a lawyer? – He don’t es n’t work as a lawyer.
  • Is your father a lawyer? – He does not work as a lawyer.

s ending in verbs Present simple in English has its own nuances of use and pronunciation, which the table below will help us understand.

Category Rule Example
Spelling Verbs ending in the letters o, x or letter combinations –ch, sh, ss, zz, tch require the ending in the form – es. Father wash es (wash) his car once a week – FatherwashesmycaronceVa week.
Predicates that end in –y have two spellings. If there is a vowel before –y in a word, then no changes occur, just an s is added to the ending. In verbs with a consonant preceding y, the transformation occurs y→I, and then the addition of -es. Jackplay s (pl ay ) basketballverywell – Jack plays basketball very well.

The rule appl ies (app ly ) to verbs and nouns – The rule applies to verbs and nouns.

Pronunciation The ending s is read as [s]( Russian with) in cases where it is preceded by a voiceless consonant.

works, sleeps, calls, stops andT.P.

My little son always sleep s with toys.

My little son always sleeps with toys

The ending s is read as [z]( Russian z), if it is preceded by a pronounced vowel or voiced consonant.

opens, reads, plays, sings andT.P.

She play s tennis twice a week.

She plays tennis twice a week.

The ending es is pronounced like (iz).

The additional es should not be confused with simply adding an s to a verb with an unpronounceable e.

He usually watch es (from) horror movies.

He usually watches horror films.

She like s (c) to dance.

She likes to dance.

At the end of the section, we note that in the third person the verbs have (3 l. - has) and to be (3 l. - is, in PastSimple- was). In sentences, such constructions are often shortened to form the ending ‘s. It s(is/was) a pen. He s(has) learned 10 words.

Ending s in nouns

The second most popular way to meet the English ending is to pluralize the noun or put it in the possessive case. In both cases, nouns in English have the letter s added to their stem.

Typically, the plural is formed by adding a simple s. But, if we take a noun ending in sh, tch, ss, ch, x, o, then the ending, as in the case of verbs, turns into es. Borrowed nouns ending in –o play an important role here. They, unlike the original English words, will only accept the letter s.

  • Mygrandparentsgrowpotato es andtomato es atthedacha – My grandparents grow potatoes and tomatoes in their dacha.
  • Wherearemyphoto s fromthebirthdayparty? – Where are my photos from the birthday celebration?

Another one important feature associated with nouns ending in f/fe. In most cases, they change these letters to v and end up with es. But there are some exceptions that use the letter s.

  • Therearemanyshel ves intheroom – There are many shelves in the room.
  • The cats like to walk on the roof s – CatslovewalkByroofs.

In other cases, the rules for reading, spelling and pronunciation s in English for nouns completely coincide with the table given in the verbs section.

As for possessive forms, their ending is formed using a special symbol - an apostrophe (‘). Nouns h. they get the ending -‘s, and noun. pl. h., if they already end in s they receive only an apostrophe.

  • I remember my parents’ advice – II rememberadvicemyparents.
  • Jack’s life is very interesting – LifeJackVeryinteresting.

Endings ed and ing

AND the last part speeches that English grammar has endowed with endings are adjectives with endings ed and ing. The roots of their formation lie in verbs, so they can rightfully be called participles. These adjectives in English are characterized by the expression of active or performed actions, which corresponds to Russian active and passive participles. At their core, both types of these words are the same, and differ only in the additional endings. Therefore, it is important to understand what these endings hide within themselves.

Adjectives with ending ing convey the characteristics of a person/object, its ability to take active action and influence someone. The expression answers the question “Which one?” and refers to the object of speech, not the speaker. It is noteworthy that the form of the word completely coincides with the English present participle (participle I).

  • I watched an interesting film yesterday – Ilookedyesterdayinterestingmovie.
  • This lesson is very boring – ThislessonVeryboring.
  • It was an amazing evening – Thiswasamazingevening.

Adjectives with ed in English express the opposite side: the effect exerted by the object. With their help, the speaker describes his state; the impression made on him by the subject of conversation. Such constructions correspond to the form of the participle in the past tense (participle II).

  • She was disappointed that her boyfriend hadn’t called her – Shewasdisappointedthose, WhatherboyNotcalledto her.
  • I was surprised that all my books were sold for 2 weeks– Iwassurprisedthat, WhatAllmybooksweresold outbehind2 weeks.
  • My little brother is tired of his homework – MyJrBrothertiredfromhishomework.

Examples show that the meaning of the entire statement depends on the use of the ending. Therefore, it is necessary to be able to navigate when the endings ed and ing are used.

As we learned from the material, endings in English have important function and can correspond to three parts of speech. Let's check your understanding of the theory by completing small exercises.

English belongs to the category of analytical languages: grammatical connections it is expressed not by changing the word and adding various morphemes (prefixes, suffixes, endings) to it, but with the help of various function words— prepositions, modal and auxiliary verbs. And therefore there are not so many endings in the English language - only three: -s (-es), -ed And -ing. For comparison, Russian is in synthetic language, and it is the morphemes that carry the grammatical load in it.

So, let's look at the most common cases of using English endings.

Ending -s (-es)

The ending -s (-es) can be found in the following cases:

Plural nouns

Almost all nouns form their plural by adding -s (-es). For example:

dog - dog s

book - book s

When a word ends in -ss, -x, -z, -ch, -sh or -o, the ending takes the form -es. For example:

Church es

box - box es

tomato - tomato es

Verbs in the 3rd person singular in the Present Simple tense

Used when talking about events that happen constantly, every day, systematically. It uses the base form of the verb, and in the 3rd person singular (he, she, it) also adds the ending -s (-es) as a verb ending. For example:

She play s every tennis weekend. — She plays tennis every weekend.

Sometimes my grandmother watch es soap operas — Sometimes my grandmother watches soap operas.

Possessive case of nouns

By and large, the ending of the possessive case should be considered separately, since it has a different history and is written through apostrophe ("). For example:

John 's car - John's car

My daughter "s book - my daughter's book

If a word ends in -s or initially ends in -s, only an apostrophe is placed at the end of the word. For example:

Her parent s" house - her parents' house

Jam s' coat - James' coat

In this case, the ending is read in full in all cases: [‘pɛːr(ə)ntsiz], [‘dʒeɪmziz].

Ending -ed

Second form of the regular verb

This form is used to express . For example:

Yesterday he paint ed the window frame. — Yesterday he painted the window frame.

Third form of regular verb (past participle)

Used in - Present Perfect, Past Perfect and others. For example:

She has lived ed here since childhood. — She has lived here since childhood.

The rain had stopp ed when we left home. — The rain stopped when we left the house.

The past participle often acts as a modifier.

For example:

Clos ed door - closed door

Well-dress ed woman - well dressed woman

Ending -ing

Fourth form of any verb (present participle)

As you know, the fourth form of the verb is used in the group of continuous tenses. For example:

She is sleeping ing now. - She's sleeping now. (Present Continuous)

Yesterday at six I was wash ing my car. — Yesterday at 6 I was washing the car. (Past Continuous)

The present participle can also play the role of a modifier. For example:

Bark ing dog - barking dog

Bloom ing tree - flowering tree

Gerund/verbal adjective

Swim ing is good for health. — Swimming is good for health.

I like eat ing outdoors. — I like to eat in the fresh air.

If you don’t yet know in what cases an apostrophe is used in English, then this article is just for you. Here we will pay attention to everyone possible ways the use of an apostrophe, because sometimes even such a small thing can change the meaning of an entire sentence.

This little comma brings so many problems that even the British themselves are clutching their heads. An apostrophe is placed in two cases:

Ownership of the item;
to shorten;

Now let's pay attention to each individual case. So, if we are talking about the ownership of an object, at the end of the word being defined it is necessary to put an apostrophe + s (’s).

This is Tim's house. - This is Tim's house.
His brother’ bike is brand new. – His brother’s motorcycle is completely new.
It was Jeannie's idea. - It was Jenny's idea.
The girl's toys were new and interesting. – The girl’s toys were new and interesting.

Note the apostrophe before the s and the apostrophe after the s.

An apostrophe is placed before s if we are talking about the singular. If the apostrophe comes after the s, then remember that this is a plural matter.

I bought several books and all the books’ covers were red. – I bought several books, and all the book covers were red.

I bought a book and book’s cover was red. – I bought a book, and the book cover was red.

My brothers’ jobs (my two brothers) were connected with advertising. – My brothers’ work was related to advertising.

My brother’s job was connected with advertising. – My brother’s work was related to advertising.

He found something and it was the eagle’s feather. “Oh, I found something, and it was an eagle feather.”

The author's books appeared in Mr. Smith's review article. – Author's books appeared in Mr. Smith's review article.

Please note if the singular word already ends in s, there are two options for the development of the situation:

Add apostrophe + s;
add an apostrophe.

Both options occur in English.

Mr. Williams's dog ate Chris's writing assignment. – Mr. Williamson’s dog ate Chris’s writing assignment.

Mr. Williams’ dog ate Chris’ writing assignment. – Mr. Williamson’s dog ate Chris’s writing assignment.

Add apostrophe to plural nouns to show that they are the owner:

Cats' tails are very long. -Cat tails are very long.

The Williams’ dog ate all the students’ writing assignment. – The Williamsons’ dog ate all the students’ written assignments.

In compound words and expressions, add an apostrophe + s

The basketball player’s performance was incredible. – The basketball player’s performance was amazing.

His father-in-law’s business is very successful. – My father-in-law’s business is very successful.

In the case of individual ownership of something, an apostrophe + s is added to each owner:

Dan’s and Sharon’s writing assignments are the best in the class. – Writing assignment Dana and Sharon are top of the class (two different tasks written by two different people).

When contracting two words are joined into one using an apostrophe:

You + are = you're
I + am = I’m
Will + not = won't
Did + not = didn’t
He + is = he's
He + has = he's
We + have = we've
Who + is = who's
Let + us = let's

The abbreviation replaces the archaic expression “ of the clock”.

Don't confuse " it is”, “it has" And " its" In the abbreviated version, the first two look exactly the same - it’s, the third expresses belonging. The difference between them is obvious:

“That noise? It's just the dog eating its bone" (What's that noise? It's a dog chewing on its bone)

Please note the following sentence:

The childrens ball fell into the two neighbor’s yard.

Do you think it is composed correctly or not? But no.

In the first part of the sentence you need to write children's(the ball belongs to the children), in the second part of the sentence there is also an error, because from the context it is clear that there are two neighbors in the yard, which means it must be neighbors' yard.

I hope you have understood the difficult topic of apostrophe in English. All that remains is to consolidate the knowledge in practice.