Conditional
tenses are used to speculate about what could happen, what might have happened,
and what we wish would happen. In English, most sentences using the conditional
contain the word if. Many conditional forms in English are used in
sentences that include verbs in one of the past tenses. This usage is referred
to as "the
unreal past" because we use a past tense but we are not
actually referring to something that happened in the past. There are five main
ways of constructing conditional sentences in English. In all cases, these
sentences are made up of an if clause and a main clause. In
many negative conditional sentences, there is an equivalent sentence
construction using
"unless" instead of "if".
|
Conditional
sentence type
|
Usage
|
If clause verb
tense
|
Main clause verb
tense
|
|
Zero
|
General truths
|
Simple present
|
Simple present
|
|
Type 1
|
A possible condition
and its probable result
|
Simple present
|
Simple future
|
|
Type 2
|
A hypothetical
condition and its probable result
|
Simple past
|
Present conditional
or Present continuous conditional
|
|
Type 3
|
An unreal past
condition and its probable result in the past
|
Past perfect
|
Perfect conditional
|
|
Mixed type
|
An unreal past
condition and its probable result in the present
|
Past perfect
|
Present contditional
|
THE ZERO CONDITIONAL
The zero conditional is used for when the time being referred to is now
or always and the situation is real and possible. The zero
conditional is often used to refer to general truths. The tense in both parts
of the sentence is the simple present. In zero conditional sentences, the word
"if" can usually be replaced by the word "when" without
changing the meaning.
|
If clause
|
Main clause
|
|
If + simple present
|
simple present
|
|
If this thing
happens
|
that thing happens.
|
|
If you heat ice
|
it melts.
|
|
If it rains
|
the grass gets wet.
|
Read more
about how to use
the zero conditional.
TYPE 1 CONDITIONAL
The type 1 conditional is used to refer to the present or future where
the situation is real. The type 1 conditional refers to a possible
condition and its probable result. In these sentences the if clause is in the
simple present, and the main clause is in the simple future.
|
If clause
|
Main clause
|
|
If + simple present
|
simple future
|
|
If this thing
happens
|
that thing will
happen.
|
|
If you don't hurry
|
you will miss the
train.
|
|
If it rains today
|
you will get wet.
|
Read more
about how to use
the type 1 conditional.
TYPE 2 CONDITIONAL
The type 2 conditional is used to refer to a time that is now or
any time, and a situation that is unreal. These sentences are
not based on fact. The type 2 conditional is used to refer to a hypothetical
condition and its probable result. In type 2 conditional sentences, the if
clause uses the simple past, and the main clause uses the present conditional.
|
If clause
|
Main clause
|
|
If + simple past
|
present conditional
or present continuous conditional
|
|
If this thing
happened
|
that thing would
happen. (but I'm not sure this thing will happen) OR
that thing would be happening. |
|
If you went to bed
earlier
|
you would not be so
tired.
|
|
If it rained
|
you would get wet.
|
|
If I spoke Italian
|
I would be working
in Italy.
|
Read more
about how to use
the type 2 conditional with the present conditional and how to use the
present continuous conditional in type 2 conditional sentence.
TYPE 3 CONDITIONAL
The type 3 conditional is used to refer to a time that is in the
past, and a situation that is contrary to reality. The facts
they are based on are the opposite of what is expressed. The type 3 conditional
is used to refer to an unreal past condition and its probable past result. In
type 3 conditional sentences, the if clause uses the past perfect, and the main
clause uses the perfect conditional.
|
If clause
|
Main clause
|
|
If + past perfect
|
perfect conditional
or perfect continuous conditional
|
|
If this thing had
happened
|
that thing would
have happened. (but neither of those things really happened) OR
that thing would have been happening. |
|
If you had studied
harder
|
you would have
passed the exam.
|
|
If it had rained
|
you would have
gotten wet.
|
|
If I had accepted
that promotion
|
I would have been
working in Milan.
|
Read more
about how to use
the type 3 conditional with the perfect conditional tense, and how to use
the perfect continuous conditional in type 3 conditional
sentences.
MIXED TYPE CONDITIONAL
The mixed type conditional is used to refer to a time that is in
the past, and a situation that is ongoing into the present. The
facts they are based on are the opposite of what is expressed. The mixed type
conditional is used to refer to an unreal past condition and its probable
result in the present. In mixed type conditional sentences, the if clause uses
the past perfect, and the main clause uses the present conditional.
|
If clause
|
Main clause
|
|
If + past perfect or
simple past
|
present conditional
or perfect conditional
|
|
If this thing had
happened
|
that thing would
happen. (but this thing didn't happen so that thing isn't happening)
|
|
If I had worked
harder at school
|
I would have a
better job now.
|
|
If we had looked at
the map
|
we wouldn't be lost.
|
|
If you weren't
afraid of spiders
|
you would have picked it up and put it outside.
|
