Introduction
Conditional sentences describe situations and their consequences. They have a condition clause - usually introduced by if, but also by words like unless, provided or as long as (see below) - and a result clause. English has four standard conditional types plus mixed conditionals, each suited to a different degree of reality or time frame.
| Type | Reality | If-clause | Result clause |
|---|---|---|---|
| Zero | Always true / facts | present simple | present simple |
| First | Real, likely future | present simple | will + base verb |
| Second | Hypothetical / unlikely present or future | past simple | would + base verb |
| Third | Unreal past / regret | past perfect | would have + past participle |
- Zero: If you heat ice, it melts.
- First: If it rains, I will take an umbrella.
- Second: If I won the lottery, I would travel the world.
- Third: If she had studied, she would have passed.
Common Mistakes with Conditionals
- If it will rain, I'll stay in.If it rains, I'll stay in.no will in the if-clause
- If I would be rich, I'd travel.If I were rich, I'd travel.second conditional
- If she would have studied, she'd have passed.If she had studied, she would have passed.third conditional
The if-clause normally doesn't take will or would. Use present simple for first conditional, past simple for second, and past perfect for third. The exceptions are polite fixed phrases where will/would means willingness, not future: If you would like to wait, the doctor will see you soon. / If you'll excuse me, I have to go.
Variations: Unless, Provided, As Long As
Several conjunctions and phrases can replace if to introduce conditions with a different nuance.
| Word/Phrase | Meaning | Example |
|---|---|---|
| unless | if not | Unless you hurry, we'll miss it. |
| provided (that) | on the condition that | You can borrow it provided you return it. |
| as long as | only if / on condition that | You can stay as long as you're quiet. |
| in case | as a precaution (not a real condition) | Take an umbrella in case it rains. |
| even if | regardless of whether | Even if I'm tired, I'll finish. |
| whether or not | in both cases | I'll go whether or not it rains. |
Practice
The zero conditional is used for ___.
Which is correct for a first conditional?
When the if-clause describes a future condition, it normally doesn't use ___.
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