Conditional Sentences
What Are
Conditional Sentences?
Conditional
sentences (also known as conditional clauses or if clauses) are
made up of two halves. One half (the half with the word if in) is a
condition, and the other half (the main clause) states the action to occur if
the condition is fulfilled.
The most
common kind of conditional sentence that you are likely to meet will contain
two clauses, one of which will start with the word if, as in If
it rains, we'll have to stay at home.
The clause without the if is the main clause of the sentence,
while the if clause is subordinate. The order of
the two clauses is generally not that important to the meaning of the sentence;
so we can switch the if clause to the end of the sentence if
we want to.
Most grammar
books tend to recognise four basic configurations of tenses in conditional
sentences which vary in structure according to the time that we are talking
about (past, present or future) and the meaning. These four types are normally
referred to as the zero,
first, second and third conditionals; we will look at the forms and
meanings of each of these in turn and also examine some of the alternatives to
these four basic types.
The Types of Conditional Sentence
1. First-type conditionals
The basic form for this type of conditional sentence can be seen in the chart below. As before, the order of the clauses can be changed with no change in meaning. This type refers to future possibilities that are certain or probable.
First-type conditionals |
|
If clause |
Main or conditional clause |
If + Present tense
|
Future tense
|
If they don't arrive
soon
If they are late
|
we'll leave without
them.
I'm going to be
angry.
|
Examples:
1) If Randy has the money, he will buy a Ferrari.
2) If I
study, I'll pass the
exam.
3) If I
don't study, I'll fail
the exam.
4) If
the bell rings, I’ll go home.
5) If
they invite you, will you come?
2. Second-type conditionals
This type is often called the hypothetical or 'unreal' future conditional since it is usually used to speculate about either very unlikely future situations or present and future impossibilities.
Second-type conditionals |
|
If clause |
Main or conditional clause |
If + Past tense
|
would + verb
|
If I had time
If I had wings
|
I would drop you off
at school.
I would fly.
|
Examples:
1) If
you swallowed some of the cleaning fluid, it would kill you.
2) If I
didn't study, I'd fail
the exam.
3) If I
didn’t have home work to do, I would call him.
4) He would
help the poor if he were a millionare.
5) If I
had a lot of money, I wouldn’t stay here.
3. Third-type conditionals
This type refers to hypothetical situations in the past. In this case we use the Past Perfect tenses in the if clause and would + have in the main clause.
Third-type conditionals |
|
If clause |
Main or conditional clause |
If + Past Perfect tense
|
would have + past participle
|
If I had known about
his condition
If we had known
about the storm
|
I would have phoned
for you earlier.
we wouldn't have
started our journey.
|
The main uses of the third conditional
are for speculating about the past, expressing regrets, excusing our own
actions and criticising others. Some of the uses tend to overlap in practice as
the examples below demonstrate:
1) If I hadn't studied, I'd have failed
the exam.
2) If
you had remembered to invite me, I would have attended your party.
3) If
he had asked you for forgiveness, would you have forgiven him?
4) Had
I gone to the party, I would have met him.
5) If he had been careful, he
wouldn't have had that terrible accident.
Remember!
(1) The
conditional construction does not normally use will or would in
if-clauses.
(2) For the
second conditional, were replaces was:
(3) After if,
we can either use "some(-one, -where...)" or "any(-one,
-where...).
(4) Instead of if
not, we can use unless.
(5) There is a
"mixed type" as well, for the present results of an unreal condition
in the past: If + Past Perfect - would + inf.
Source:
http://grammar.ccc.commnet.edu/grammar/conditional2.htm
https://www.tesol-direct.com/guide-to-english-grammar/conditional-sentences
http://www.grammar-monster.com/glossary/conditional_sentences.htm
