A Conjunction is a word used to join words, groups of words or sentences.
(i) I helped him because he was needy.
(ii) Ratna is studying but her brother is playing.
(iii) John and David are good friends.
(iv) Do you know that he is a man of knowledge?
All the italicised words are conjunctions because they join words, groups of words or sentences.
KINDS OF CONJUNCTIONS
1. Co-ordinating Conjunction
2. Sub-ordinating Conjunction
1. Co-ordinating conjunctions are conjunctions which join two words or sentences of equal rank or order together.
Take the first pair of sentences. The sentences “The sun rises in the east.” and “The sun sets in the west.” are two independent sentences, each can stand alone. They are of equal rank or order. None of the part depends on the other for its complete meaning. If we join these two independent sentences by the word and, we make one sentence. “The sun rises in the east and sets in the west.” Here, the joining word and is a Co-ordinating Conjunction.
In other pair of sentences also words like but, or and yet join together the sentences of equal rank or order. Therefore, they are all Co-ordinating Conjunctions.
We also call a conjunction co-ordinating when it joins single words together because single words are of the same rank or order.
Two and two make four.
Time and tide wait for none.
In the above sentences, the word and is a co-ordinating conjunction.
2. Sub-ordinating Conjunctions are conjunctions which join two sentences of unequal rank or order. One of the two is dependent upon, or subordinate to, the other.
Take the first sentence. It contains two statements—
In other sentences also, the words like if, though and unless join two sentences of unequal rank or order. Therefore, they are all Sub-ordinating conjunctions.
Note: The sub-ordinating conjunction is always the first word in the dependent sentence.