CONDITIONAL SENTENCES
Conditional sentences are used to indicate situations, generally hypothetical, with differing degrees of
probability/certainty. They also express different periods of time.
There are 4 types of conditional sentences: types 0, 1, 2 and 3:
Type 0 If I go to London, I stay at the Savoy. (fact, 100% certain, no specific time frame)
Type 1 If I go to London, I’ll stay at the Savoy. (90% probability, future)
Type 2 If I went to London, I’d stay at the Savoy. (45% probability, present)
Type 3 If I’d gone to London, I’d have stayed at the Savoy. (0% probability, past)
Mixed conditionals are also possible, and are used when referring to two different periods of time:
Types 3&2 If you hadn’t gone to bed so late last night, you wouldn’t be feeling
so tired this morning.
* * * * * * *
Conditional sentences have two principal parts, the ‘if’ clause, and the ‘main’ clause. These two parts can be inverted:
If it rains, she’ll take a taxi.
She’ll take a taxi if it rains.
In written English, when a conditional sentence begins with an ‘if’ clause, then a comma must separate it from the
following ‘main’ clause.
The word ‘if’ in the ‘if’ clause can be substituted by other words or expressions, including unless, before, until, when,
as soon as, once and after, but this is normally limited to Type 0 and Type 1 conditionals. This obviously changes the
meaning of the sentence, but not the structure.
* * * * * * *
Sometimes a conditional sentence can also include a third clause which serves as an introduction to one of the other
two clauses:
I think (that) she’ll take a taxi if it rains.
I think (that) if it rains, she’ll take a taxi.
If it rains, I think (that) she’ll take a taxi.
