Future Time Clauses

An English clause is a group of words with a subject and a verb. There are two types: independent and dependent. An independent clause expresses a complete thought, begins with a capital letter and ends with a period, question mark or exclamation mark. In other words, it is a complete sentence. However, a dependent clause, although it also contains a subject and a verb, does not express a complete thought. Therefore it cannot stand alone; it must be joined to an independent clause. See the example clauses below.

It was raining (independent clause) when I left the house this morning. (dependent clause)
She went home early (independent clause) because she didn't feel well. (dependent clause)

In these examples, the dependent clauses follow the independent clauses. However, you can start a sentence with a dependent clause as long as you separate it from the independent (or main) clause with a comma, as in the examples below.

When I left the house this morning, it was raining.
Because she didn't feel well, she went home early.

Future time clauses are dependent clauses that must be joined to independent (main) clauses. It is customary to the future tense in the independent clause and the present tense in the dependent (time) clause. Do not use the future tense in the time clause. Study the examples below. In each case, the independent (main) clause is in bold type.

Future time clauses begin with time words such as when, as soon as, after, before, until, and while. Below are a few example sentences. As you saw earlier, a comma separates the time clause from the main (independent) clause when the time clause comes first.