Conditionals

Form

A conditional sentence pairs an if-clause (the condition) with a main clause (the result), and the two tenses you pick show how real the situation is.

The zero conditional puts present simple in both halves for something always true (If you heat ice, it melts). The first conditional uses if plus present simple with will for a real future possibility (If it rains, we will cancel); the second uses if plus past simple with would for something imaginary or unlikely now (If I had more time, I would learn to paint); and the third uses if plus past perfect with would have plus a past participle for a past that cannot be changed (If they had left earlier, they would have avoided the traffic). A mixed conditional takes its halves from two different types, most often a past condition with a present result (If I had taken that job, I would be richer now).

When to Use It

1. 1

   Use the zero conditional for facts and rules that are always true, with present simple in both halves

   If you heat ice, it melts.

2. 2

   Use the first conditional for a real future possibility, with present simple after if and will in the result

   If she passes the exam, she will be accepted.

3. 3

   Use the second conditional for something imaginary or unlikely now, with past simple after if and would in the result

   If I won the lottery, I would live abroad.

4. 4

   Use the third conditional to imagine a different past, with past perfect after if and would have in the result

   If I had known, I would have helped.

5. 5

   Mix the types when the condition and the result sit in different times

   If I had taken that job, I would be richer now.

6. 6

   Use unless in place of if not, and were I or had I for a formal tone

   Had I known about the delay, I would have booked another flight.

Common Mistakes

• Will after if: write If it rains, we will cancel, not If it will rain, we will cancel — the if-clause stays in the present even though it points at the future.
• Would in the if-clause: write If we had a bigger budget, we would hire two more people, not If we would have a bigger budget — would belongs in the result half only.
• Was for were: write If I were you, I would apologize, not If I was you, I would apologize — were is the standard form in a hypothetical, and “If I were you” is a fixed phrase.
• Would have in both halves: write If I had set my alarm, I wouldn't have overslept, not If I would have set my alarm — the condition takes the past perfect.
• Double negative with unless: write Unless you hurry, you will miss the flight, not Unless you don't hurry, you will miss the flight — unless already means if not.