If-clauses
If-clauses are used to talk about conditions. Note that an if-clause is an example of a subordinate adverb clause. Sentences containing an if-clause are sometimes called conditional sentences.
There are mainly four types of conditional sentences in English.
- Zero conditional
- First conditional
- Second conditional
- Third conditional
The zero conditional is used to talk about conditions that are always true. In this case, we use a simple present tense in the if-clause and the result clause.
- If I need help, I call her.
Conditional sentences are very common in English and therefore you should know how to use them correctly. In this lesson we will take a look at the most common conditional forms.
First conditional
Incorrect: If it rains we would cancel the match.
Correct: If it rains we will cancel the match.
Incorrect: If you hit the dog, it would bite you.
Correct: If you hit the dog, it will bite you.
Incorrect: If you invite her, she would come.
Correct: If you invite her, she will come.
Incorrect: If you ask more politely, she would help.
Correct: If you ask more politely, she will help.
When the verb in the if-clause is in the simple present tense, we use will/shall/can/may + infinitive in the main clause.
Second conditional
Incorrect: If you studied hard, you will get a first class.
Correct: If you studied hard, you would get a first class.
Incorrect: If she spoke English, she will get a good job.
Correct: If she spoke English, she would get a good job.
Incorrect: If I knew the answer, I would have told you.
Correct: If I knew the answer, I would tell you.
When the verb in the if-clause is in the simple past tense, we use would/should/could/might + infinitive in the main clause. Sentences of these types are used to talk about purely imaginary situations.
Third conditional
Incorrect: If you had studied hard, you would get a first class.
Correct: If you had studied hard, you would have got a first class.
Incorrect: If you had invited her, she would come.
Correct: If you had invited her, she would have come.
When the verb in the main clause is in the past perfect tense, we use would/should/could/might + have + infinitive in the main clause.