Conditional structures are used to talk about a condition and a possible result or consequence. The condition is something that must happen first in order for something else to happen as a result or consequence. Conditionals are complex sentences, which consist of an if-clause, followed by a main clause. Either clause can be positive or negative.
۱) Zero conditional
|if + present tense + present tense|
|If you heat water to 100 degrees, it boils.|
|present tense + if + present tense|
|Water boils if you heat it to 100 degrees.|
Zero conditional is used to talk about factual or true information. We use the same tense (present or past) in both the if-clause and the main clause (if has a similar meaning to every time):
If you cool water below zero degrees, it freezes.
We can also use when to introduce the condition:
When you visit a place of worship, you dress appropriately.
If it is no longer a fact we use the past tense:
When I was a child, if I was naughty, my parents sent me to bed early.
۲) First conditional
|if + present tense + will/won’t (might/could/going to) + verb|
|If you invest your money, it will grow.|
|will/won’t (might/could/going to) + verb + if + present tense|
|Your money will grow if you invest it.|
First conditional is used to talk about future situations based on conditions. We use the present tense in the if-clause and a future form in the main clause:
If the world continues to burn fossil fuels at the current rate, global warming will rise to two degrees Celsius by 2036.
We can use might, may, or could instead of will to suggest something is less probable:
If it’s foggy tonight, the plane may be late.
or can to mean sometimes:
If you travel on weekends, the roads can be very crowded. (this sometimes happens)
۳) Second conditional
|if + past tense + would(n’t) (might/could) + verb|
|If you invested your money, it would grow.|
|would(n’t) (might/could) + verb + if + past tense|
|Your money would grow if you invested it.|
Second conditional is used to talk about something that’s imaginary, impossible or unlikely in the present or future. The past tense in the if-clause does not refer to past time:
If I won £۱۰۰,۰۰۰, I would give up my job.
Note: with the verb be we can use was or were with I/he/she/it:
If I were/was you, I would buy a car.
We can use was/were + infinitive to refer to an improbable action:
If I were to win one million dollars, I would give up my job.
۴) Third conditional
|if + past perfect + would(n’t) have + past participle|
|If you’d asked me, I’d have done it.|
|would(n’t) have + past participle + if + past perfect|
|I’d have done it if you’d asked me.|
Third conditional is used to speculate about past events. It is often used to express regret or to imagine the result of something that did not happen:
If she had been in her office, I would have seen her. (= she was not in her office so I didn’t see her)
In the main clause we can use might or could to say that something was less certain:
If I’d asked her, she might have helped me. (possibility)
۵) Mixed conditional
|if + past perfect + would(n’t) + verb|
|If you’d saved more, you’d be rich.|
|if + past simple + would(n’t) have + past participle|
|If you were sensible, you’d have saved more.|
|if + past perfect + would(n’t) be + ing|
|If you hadn’t saved, you wouldn’t be going on holiday.|
|if + past continuous + would(n’t) + verb|
|If you were going on holiday soon, you’d be happy.|
|if + past simple + would(n’t) be + ing|
|If you didn’t have savings, you wouldn’t be going on holiday.|
Mixed conditional is used to express the present result of a past situation or explain how a present situation affected a past action. To do this we use a combination of second and third conditionals.
The present result of an imagined situation or action in the past (past situation + present result):
If I’d taken the medication as prescribed, I wouldn’t be still sick. (= I didn’t take the medication as prescribed so now I am still sick)
The past result of an imagined situation in the present (present situation + past result):
If I had more confidence, I would have got the job. (= I don’t have enough confidence so I didn’t get the job)
The future result of an imagined situation or action in the past (past situation + future result):
If I hadn’t broken my leg, I’d be playing football latter. (= I did break my leg so I am not playing football later)
The present result of an imagined situation or action in the future (future situation + present result):
If I wasn’t meeting my mentor later, I’d be on vacation now. (= I am meeting my mentor later, so I’m not on vacation now)
The future result of an imagined situation in the present (present situation + future result):
If I was in London, I’d be going to Trafalgar Square tomorrow because it’s St Patrick’s Day. (= I am not in London, so I won’t be going to Trafalgar Square tomorrow)
Conditional structures are usually presented as types (zero, first, second, third, mixed) using specific structures. It is important to remember that these specific structures are a general guide and that different tenses can be used in the condition clause. There are also alternatives to will/would in the result clause.
Conditional structures can be useful for the IELTS Writing Task 2 to express facts or unreal situations based on conditions or to speculate on results or consequences in the future or past.