Conjunction

Conjunctions are words which join phrases, clauses and sentences.^[1]

Conjunctions have three basic forms which are shown in the table below.^[2]

Form	Words	Sentences
Single Word	and, but, because, although, or, so, for, etc.	Do you want chips or cake?
Compound	provided that, as long as, in order that/to, etc.	You need to exercise in order to lose weight.
Correlative^[3]^[4]	both/and, either/or, neither/nor, if/then, not/but, not only/but also	Either Monday or Tuesday is fine. Not only should you eat fruit, but also vegetables.

Conjunctions also have two functions, as shown below.^[1]^[2]

Type	Function	Position	Example Sentences
Coordinating conjunctions	Join equal (independent) parts of a sentence.	Always come between the words/clauses that they join.	Jack and Jill went up the hill. The water was warm, but I didn't go swimming.
Subordinating conjunctions	Join subordinate clauses to main clauses.	Usually come at the beginning of subordinate clauses.	I went swimming although it was cold.

Although some people say it's not correct to use conjunctions at the beginning of a sentences, many famous writers do so.^[1]^[2]

References