Conjunction:
A conjunction is a part of speech or word that connects –
- One word to another word.
- One word to another clause.
- One sentence to another sentence.

Conjunction হচ্ছে এমন শব্দসমূহ যারা এক শব্দকে অন্য শব্দের সাথে, এক শব্দকে অন্য clause এর সাথে বা এক Sentence কে অন্য Sentence এর সাথে সংযুক্ত করে।

The conjunctions are and, but, or, for, nor, so, yet, because, if, whether, lest, unless, as, since, how, when, where, while, why, till, until, after, before, however, as soon as, though and than.

Example:
One word to another word:
- Rupom and Rifat are two brothers. (noun to noun)
- Rimi and you have done this work. (Noun to pronoun)
- You and I will go there. (Pronoun to pronoun)
- The old man sat down and wept. (verb to verb)
- We are sad but hopeful. (adjective to adjective)
- A cat moves slowly and silently. (Adverb to adverb)
- The bird flies through and through the sky. (preposition to preposition)

One word to another clause:
- He is so weak that he cannot walk.
- Such was her beauty that everybody loved her.

One sentence to another sentence:
- I trust him because he is honest.
- He says that he will do it.
- They will come if they are allowed here.
- It is a long time since I saw you last.
- You must wait here until your father comes back.
- I wish to know whether he will come or not.

There are different types of conjunctions:

- Coordinate Conjunction
- Subordinate Conjunction
- Correlative conjunction

Coordinate Conjunction:

Coordinate conjunctions such as and, but, or, nor, for, so, or yet are used to join individual words, phrases and independent clauses.

Example:
- She stood first and got a prize.
- He is sad but hopeful.
- The snake is small but dangerous.
- You must read or you may fail in the examination.

Subordinate Conjunction:

The subordinate clause such as since, because, although, as, until etc. are used to join an independent clause to a dependent clause.

The subordinate conjunctions are used before the dependent clauses. Dependent clause can be placed before or after the independent clauses.

Example:
- He never gives up until he wins.
- Since she had the headache, she did not go to work.
- Though he loved her cousin, he married another one.
- Despite calling several times, she never received a replay.

Correlative conjunctions:

Correlative conjunctions are pairs of conjunctions such as both…and, either…..or, neither……nor etc. They are used in the sentences to link words, phrases and clauses.

Correlative conjunctions connect two words or phrases or clauses that have the similar structure and are grammatically similar. That means nouns are linked to nouns, adjectives to adjectives, prepositional phrases to prepositional phrases.

Correlatives conjunctions are:
Both….and, either….or, neither….nor, not only….but also, so….that, such….that, no sooner….than, hardly….when, scarcely….when, else….than, else….but.

Example:
- He is both a fool and a knave. (noun to noun)
- She is both wise and good. (adjective to adjective)
- He must either work or go. (verb to verb)
- He behaved neither wisely nor kindly. (adverb to adverb)
- He is so tired that he cannot run.
- Such was her beauty that everybody loved her.
- No sooner had I sat down than they left the room.
- Hardly had I left the room when it began to rain.
- Scarcely had I left the room when it began to rain.
- She has none else than her mother.
- She has none else but her mother.