The short, simple conjunctions are called "coordinating conjunctions":
A coordinating conjunction joins parts of a sentence (for example words or independent clauses) that are grammatically equal or similar. A coordinating conjunction shows that the elements it joins are similar in importance and structure:
Look at these examples - the two elements that the coordinating conjunction joins are shown in square brackets [ ]:
Coordinating conjunctions always come between the words or clauses that they join.
When a coordinating conjunction joins independent clauses, it is always correct to place a comma before the conjunction:
However, if the independent clauses are short and well-balanced, a comma is not really essential:
When "and" is used with the last word of a list, a comma is optional:
The 7 coordinating conjunctions are short, simple words. They have only two or three letters. There's an easy way to remember them - their initials spell: