'IF'
SENTENCES AND THE 'UNREAL' PAST
In this section
you will find information on sentences containing the word 'if',
the use of conditional tenses, and the 'unreal past', that is,
when we use a past tense but we are not actually referring to past time.
IF AND
THE CONDITIONAL
There are four
main types of 'if' sentences in English:
1. The
'zero' conditional, where the tense in both parts of
the sentence is the simple present:
| 'IF'
CLAUSE
|
MAIN
CLAUSE
|
|
If + simple
present
If
you heat ice
If it rains
|
simple
present
it
melts.
you get wet
|
In these sentences,
the time is now or always and the situation is real and possible.
They are often used to refer to general truths.
2. The
Type 1 conditional, where the tense in the 'if clause
is the simple present, and the tense in the main clause is the
simple future
| 'IF'
CLAUSE
|
MAIN
CLAUSE
|
|
If + simple
present
If
it rains
If you don't hurry
|
Simple
future
you
will get wet
we will miss the train.
|
In these sentences,
the time is the present or future and the situation is
real. They refer to a possible condition and its probable
result.
3. The
Type 2 conditional, where the tense in the 'if' clause
is the simple past, and the tense in the main clause is the present
conditional:
| 'IF'
CLAUSE
|
MAIN
CLAUSE
|
|
If + simple
past
If
it rained
If you went to bed earlier
|
Present
conditional
you
would get wet
you wouldn't be so tired.
|
In these sentences,
the time is now or any time, and the situation is unreal.
They are not based on fact, and they refer to an unlikely
or hypothetical condition and its probable result.
4. The
Type 3 conditional, where the tense in the 'if' clause
is the past perfect, and the tense in the main clause is the
perfect conditional:
| 'IF'
CLAUSE
|
MAIN
CLAUSE
|
|
If + past
perfect
If
it had rained
If you had worked harder
|
Perfect
conditional
you
would have got wet
you would have passed the exam.
|
In these sentences,
the time is past, and the situation is contrary to reality.
The facts they are based on are the opposite of what is
expressed, and they refer to an unreal past condition and
its probable past result.
A further type
if 'if' sentence exists, where Type 2 and Type 3 are mixed. The
tense in the 'if' clause is the past perfect, and the tense in
the main clause is the present conditional:
| 'IF'
CLAUSE
|
MAIN
CLAUSE
|
|
If + past
perfect
If
I had worked harder at school
If we had looked at the map
|
Present
conditional
I
would have a better job now.
we wouldn't be lost.
|
In these sentences,
the time is past in the 'if' clause, and present
in the main clause. They refer to an unreal past condition
and its probable result in the present.