This document discusses different types of time clauses in English. It explains that present simple is used after time clauses referring to the future like "when", "before", "as soon as", and "until". It also explains the three conditional structures: first conditional uses "if" plus present simple for possible present or future events; second conditional uses "if" plus past simple for hypothetical or improbable events; and third conditional uses "if" plus past perfect for hypothetical past events that cannot change. Examples are provided for each conditional structure.

2. TIME CLAUSES
 For time clauses that refer to the future:
PRESENT SIMPLE after:
 When: Ex: Call me when you get home
 Before: I always have a big lunch before I go to my English class
 As soon as: Call me as soon as you get the money
 Until: I won’ t stop studying English until I speak it fluently
 After: After I finish my English course, I´ll go and live in London.

3. First conditional
 IF+ present simple (1st part)
+will+infinitive without to(2nd part)
For something possible in the present or future:
Ex: If you study, you’ll pass.
 UNLESS+ present simple (1st part)=If not
Ex.: Unless you work harder, you won’t pass

4. Second conditional
 IF+ past simple (1st part)
+would/could/+infinitive without to(2nd part)
For something hypothetical, improbable in the present
or future
Ex.: If you studied, you’d/could pass
 Were is often used with all persons (especially when
giving advice)
Ex.: If I were you, I’d go to class every day.
If I were rich, I’d buy a house with 15 bathrooms.

5. Third conditional
 IF+Past Perfect (1st part)+WOULD HAVE+past
participle: for something hypothetical about the past,
impossible to change now.
Ex.: If I had studied a little bit, I would have passed
the exam. (But I didn’t study, so I failed the exam).