1. Định nghĩa: Liên từ là từ dùng để nối các từ loại, cụm từ hay mệnh đề.
2. Phân loại: Liên từ được chia làm hai loại chính:
a. Đẳng lập (song song):
Dùng loại liên từ này để nối những các từ loại hoặc cụm từ/ nhóm từ cùng một loại, hoặc những mệnh đề ngang hàng nhau (tính từ với tính từ, danh từ với danh từ ...):
He and I are students.
She is beautiful and kind.
They are learning to read and write.
b. Liên từ phụ thuộc:
Loại liên từ phụ thuộc nối kết các nhóm từ, cụm từ hoặc mệnh đề có chức năng khác nhau - mệnh đề phụ với mệnh đề chính trong câu.
3. Những liên từ Đẳng lập (song song):
Những liên từ Đẳng lập gồm:
Ví dụ: She is a good and loyal wife.
I have many books and notebooks.
BOTH ... AND
Ví dụ: She is both good and loyal.
They learn both English and French.
AS WELL AS
Ví dụ: He has experience as well as knownledge.
NO LESS THAN
Ví dụ: You no less than he are very rich.
NOT ONLY ... BUT (ALSO)
Ví dụ: He learns not only English but but (also) Chinese.
I like playing not only tennis but (also) football.
Ví dụ: Hurry up, or you will be late.
Ví dụ: He isn't either good or kind.
I don't have either books or notebooks.
NEITHER ... NOR
Ví dụ: He drinks neither wine nor beer.
She has neither husband nor children.
Ví dụ: He is intelligent but very lazy.
She is ugly but hard-working.
Ví dụ: You have eaten nothing; then you must be very hungry.
The plant looks very faded; then it hasn't been watered for long.
Ví dụ: You didn't work hard for this term; consequently, he failed the exam.
Ví dụ: He is a very lazy student; however, he can pass all the exams easily.
It was raining very hard; however, we went out without umbrellar.
Ví dụ: She studies very hard; nevertheless, she always gets bad marks.
Ví dụ: I speak to you peaceably; still/yet you will not listen.
She says she does not love me, yet, I still love her.
OR, ELSE, OTHERWISE
Ví dụ: We have to work hard, or/else/otherwise we will fail the exam.
Ví dụ: Go where you like; only do not stay here.
Ví dụ: He violated the traffic signs, therefore he was punished.
4. Những liên từ phụ thuộc (chính phụ):
Những liên từ phụ thuộc:
Ví dụ: He will surely succeed, for (because) he works hard.
Ví dụ: He learns hard whereas his friends don't.
Wise men love truth whereas fools avoid it.
Ví dụ: Don't sing while you work.
Don't talk while you eat.
Ví dụ: We have to study hard at school; besides, we must pay attention
to physical exercise.
He stole two watches; moreover, he broke the window.
Ví dụ: He is a good teacher; so, he is very popular with students.
It rained very hard; so, we didn't go out that night.
Ví dụ: I had not money about me; hence I did not buy the book.
He came late; hence, he missed the first part of the lesson.
- Liên từ nối mệnh đề (như trạng ngữ):
a. Thời gian (Time):
Ví dụ: A man shoud take a little rest, after he has worked hard.
The ship was checked carefully after she had been built.
Ví dụ: He came her, as the clock struck six.
They left as the bell rang..
AS SOON AS
Ví dụ: I will phone you as soon as I come home.
They will get married as soon as they finish university.
Ví dụ: Don't count your chickens before they are hatchd.
He talks as if he were very wise.
Ví dụ: He has been very weak, since he was taken sick.
AS LONG AS
Ví dụ: No one can harm us, as long as we remain friends.
I will lend you some money as long as you promise to pay me back.
Ví dụ: People do not know the value of health until they lose it.
Ví dụ: When you visit this country, you should bring thick winter clothes.
Ví dụ: Make hay while the sun shines.
Step while you dance.
b. Nơi chốn (Places):