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.
1) 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.
2) 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)
3) 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 £100,000, 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.
4) 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)
5) 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.