Conditional sentences

Conditional sentences are statements discussing known factors or hypothetical situations and their consequences. Complete conditional sentences has two parts. A conditional clause (often referred to as the if-clause) and the consequence or main clause.

Conditional sentences are used to express that the action in the main clause can only take place if the condition in the if-clause is fulfilled. Always use a comma after the if-clause when the if-clause precedes the main clause.

There are 3 conditional clauses in English. They are

1. Probable Condition
2. Improbable Condition
3. Impossible Condition

Probable Condition

Probable Conditions are used to express sentences which are likely to happen in the future if the sentences in the if clause becomes true. Here the if-clause is said in simple present tense and ‘main clause’ is said in simple future tense.

The format of the sentence is

If clause (simple present tense)

If + sub + main verb or

If + sub + auxiliary verb (is, am, are, has, have, do, does)

Main clause (simple future tense)

Sub + auxiliary verb (will, shall, can, may, must) + main verb (base form)

Eg:

If you study well, you will pass.

If you tease the dog, it will bite you.

If he calls me, I must go with him.

If I have some money, I will buy a car.

If I am busy, I can’t attend the meeting.

I will write a letter to him, if I know his address.

Improbable Condition

Improbable Condition are used to express statements which are not likely to happen in the future or sentences which are completely unrealistic. Here in the if-clause we say a statement which is unreal and it will not come to reality. So the main clause sentence will not happen in the future.

The if-clause is said in simple past tense and in the main clause an auxiliary model verb (would, should, could, might) is used. The format of the sentence is

If clause

If + Sub + main verb (past) or auxiliary verb (were, had, did)

Please not that was is not used in the if-clause.

Main clause

Sub + auxiliary verb (would, should, could, might) + main verb (base form)

Eg:

If you telephoned me, I would come there.

If I knew his address, I would write a letter to him.

If they played well, they could win the match.

If I were a bird, I could fly.

If I had enough money, I would buy a car.

Impossible Condition

Impossible condition are used to refer to sentences that the present circumstances would be different if something different had happened in the past. It is said impossible condition because the sentence will not be fulfilled because it refers to something which already happened. Look at the sentence below.

If he had called me, I would have gone with him.

The first part of the sentence says about a thing that didn’t actually happen in the past. If the first part had happened the second part of the sentence would have come true but the speaker says about a sentence that are likely to happen but regrettably did not happen.

In this type of sentence we use the past participle form of the sentence in the if clause and the modal auxiliary (would have, should have, could have, might have) and past participle form of the main verb in the main clause

The format of the sentence is

If clause

If + sub + had + main verb (PP) or

If + sub + had had

Main clause

Sub + auxiliary verb (would have, should have, could have, might have) + main verb (PP)

Eg:

If you had applied for the job, you would have got it.

If they had played well, they could have won the match.

If I had had enough money, I would have bought a car.

If I were you, I would take rest.

Had I known his address, I would have written a letter to him.

Had you teased the dog, it would have bitten you.

Exceptions and Special Cases

Use of the Simple Future in the If-Clause

Generally speaking, the simple future should be used only in the main clause. One exception is when the action in the if-clause will take place after the action in the main clause. For example, consider the following sentence:

If aspirin will ease my headache, I will take a couple tonight.

The action in the if-clause is the aspirin easing the headache, which will take place only after the speaker takes them later that night.

“Were to” in the If-Clause

The verb phrase ‘were to’ is sometimes used in conditional sentences when the likely or unlikely result is particularly awful or unthinkable. In this case, ‘were to’ is used to place emphasis on this potential outcome. Consider these sentences:

If I were to be sick, I would miss another day of work.

Note that the emphatic “were to” can be used to describe hypothetical scenarios in the present, future, and past.

Punctuating Conditional Sentences

Despite the complex nature of conditional sentences, punctuating them properly is really simple!

Here’s the skinny:

Use a comma after the if-clause when the if-clause precedes the main clause.

If I’d had time, I would have cleaned the house.

If the main clause precedes the if-clause, no punctuation is necessary.

I would have cleaned the house if I’d had time.