Conjunctions have two basic functions or "jobs":

1. Coordinating conjunctions are used to join two parts of a sentence that are grammatically equal. The two parts may be single words or clauses, for example:
- Jack and Jill went up the hill.
- The water was warm, but I didn't go swimming.

2. Subordinating conjunctions are used to join a subordinate dependent clause to a main clause, for example:
- I went swimming although it was cold.