Time clauses: when / as soon as / before / after / until

Rules

• Rule 1: Time word + present simple

  when, as soon as (immediately when), before, after, until (up to the time when) → followed by the present simple. The usual rule still works: he / she / it → -s.

  Pattern: when / as soon as / before / after / until + present simple

  Example: When she arrives, we'll start.

  Example: I'll wait until the rain stops.

• Rule 2: will goes in the main clause

  The other half, the main clause, can use will for the future. It can also have can, let's or an imperative. Careful: the question word When is different: *When will you come?* is correct.

  Pattern: main clause: will / can / imperative + time clause: present simple

  Example: I will text you as soon as I land.

  Example: Close the door before you leave.

• Rule 3: Commas

  If the time clause comes first, put a comma after it. If it comes second, no comma. The meaning is the same.

  Pattern: time clause, main clause · main clause + time clause

  Example: As soon as the bus comes, we'll get on.

  Example: We'll get on as soon as the bus comes.

Common mistakes

• I'll call you when I will get home. → I'll call you when I get home.

  No will after a time word.

• Wait until I will come back. → Wait until I come back.

  until + present simple.

• As soon as she arrive, we'll eat. → As soon as she arrives, we'll eat.

  she → -s.