Look at these examples to see how zero, first and second conditionals are used.
If you freeze water, it becomes solid.
If it rains tomorrow, I'll take the car.
If I lived closer to the cinema, I would go more often.
Try this exercise to test your grammar.
- Grammar test 1
Read the explanation to learn more.
Grammar explanation
Conditionals describe the result of a certain condition. The if clause tells you the condition (If you study hard) and the main clause tells you the result (you will pass your exams). The order of the clauses does not change the meaning.
If you study hard, you will pass your exams.
You will pass your exams if you study hard.
Conditional sentences are often divided into different types.
Zero conditional
We use the zero conditional to talk about things that are generally true, especially for laws and rules.
If I drink too much coffee, I can't sleep at night.
Ice melts if you heat it.
When the sun goes down, it gets dark.
The structure is: if/when + present simple >> present simple.
First conditional
We use the first conditional when we talk about future situations we believe are real or possible.
If it doesn't rain tomorrow, we'll go to the beach.
Arsenal will be top of the league if they win.
When I finish work, I'll call you.
In first conditional sentences, the structure is usually: if/when + present simple >> will + infinitive.
It is also common to use this structure with unless, as long as, as soon as or in case instead of if.
I'll leave as soon as the babysitter arrives.
I don't want to stay in London unless I get a well-paid job.
I'll give you a key in case I'm not at home.
You can go to the party, as long as you're back by midnight.
Second conditional
The second conditional is used to imagine present or future situations that are impossible or unlikely in reality.
If we had a garden, we could have a cat.
If I won a lot of money, I'd buy a big house in the country.
I wouldn't worry if I were you.
The structure is usually: if + past simple >> + would + infinitive.
When if is followed by the verb be, it is grammatically correct to say if I were, if he were, if she were and if it were. However, it is also common to hear these structures with was, especially in the he/she form.
If I were you, I wouldn't mention it.
If she was prime minister, she would invest more money in schools.
He would travel more if he was younger.
Do this exercise to test your grammar again.
- Grammar test 2
Hello Kim Hui-jeong
These sentences are grammatically correct. Note that not all sentences with the word 'if' are conditionals. If we are not speaking about imaginary situations, we just use the normal verb tenses, i.e. the present tense to refer to the present, past tenses to refer to the past, etc. That seems to be the case in the second sentence here -- it means that since he saw her playing games, he must have seen her lying in her bed.
All the best
Kirk
The LearnEnglish Team
Hello khalid ibrahim,
As you say, we generally use a modal verb in the main clause of real/likely future conditional sentences. Typically, this is will:
However, other modal verbs than will can be used:
Your second sentence is an example of this. You could use a different modal verb in place of can, such as may.
Your first example is a little different. There are some verbs which describe our beliefs about the future which can be used in this way. We use a present form because we are describing our present views on a situation, not the result of a condition. Verbs used commonly in this way include want, expect, hope, fear and believe:
Peter
The LearnEnglish Team
Hello patph0510,
The answer to your question is on the page above. Look at the explanations for zero and first conditionals and apply them to your examples. This should answer your question for you.
Peter
The LearnEnglish Team
Hello Ira92,
The sentence is not entirely grammatical. You need to add an object after believe:
However, the sentence is still not correct in terms of standard grammar. The form is [if + past simple > (then) would verb], sometimes called a second conditional. This is used to talk about unlikely or impossible (unreal) situations in the present or future. However, this sentence refers to an unreal past as it contains the phrase a week ago. This is inconsistent. To make the sentence consistent you should use a past perfect in the first clause:
The second clause is fine as it describes an unreal present result of that unreal past situation.
Peter
The LearnEnglish Team