The rule in one minute
A conditional sentence joins a condition to a result: if this happens, that follows. English has four main patterns. Each one pairs a tense in the if-clause with a matching tense in the result.
| Pattern | Use | Example |
|---|---|---|
| Zero | Facts and general truths | If you heat ice, it melts. |
| First | Likely future | If it rains, we will stay indoors. |
| Second | Unlikely or imagined | If I won the lottery, I would travel. |
| Third | A different past | If I had studied harder, I would have passed. |
In short: zero uses the present in both halves. First uses the present, then will.
Second uses the past, then would. Third uses the past perfect (had studied), then would have plus the past participle.
If you mix halves from two patterns, the sentence breaks.
Why it costs marks
Conditionals appear whenever you discuss possibilities and results, especially in discursive and argumentative writing. Each pattern links two tenses, so errors are easy to make. The usual mistake is putting would in the if-clause.
In ESL writing, this is a direct correctness error. In First Language writing, it weakens accuracy. Correct conditionals also let you reason clearly about what might happen.
Wrong and right
- Wrong: If it will rain, we will cancel the trip. Right: If it rains, we will cancel the trip. First conditional uses the present in the if-clause.
- Wrong: If I would have more time, I would read more. Right: If I had more time, I would read more. There is no would in the if-clause.
- Wrong: If she studied harder, she will pass. Right: If she studied harder, she would pass. Match the second-conditional halves.
- Wrong: If they had left earlier, they will catch the train. Right: If they had left earlier, they would have caught the train. Third conditional in both halves.
- Correct (zero): If you mix blue and yellow, you get green. This is a general truth.
If this is where marks are going missing, a trial hour with an experienced teacher can work on it one-to-one.
Try it yourself
Correct each sentence, then check below.
- If I was rich, I would buy a house by the sea.
- If you will heat water to 100 degrees, it boils.
- If he had asked me, I would help him.
- If it snows tomorrow, school would be closed.
Answers: (1) If I were rich, I would buy a house by the sea. People often say was in speech, but were is the safe form for exams. (2) If you heat water to 100 degrees, it boils. This is a general truth, so there is no will.
(3) If he had asked me, I would have helped him. A past perfect if-clause needs would have in the result. (4) If it snows tomorrow, school will be closed. This is a likely future, so use will.
Make it a habit
Before you write, decide which pattern you need. Is it a fact (zero), a likely future (first), an imagined present (second) or a different past (third)? Once you name it, the tenses follow.
The best safety rule is simple: keep will and would out of the if-clause. They belong in the result.
Learn the four patterns as fixed shapes and practise with your own examples. When you proofread, find every if and check that both halves match.
Where students get stuck, and how we help
Students usually mix the first and second patterns, for example If I would have time. In our English as a Second Language lessons, a teacher builds conditional practice into the discursive writing you are already doing and corrects the pattern in your own sentences.
Lessons start from RM70/hr. You can book a paid one-hour trial to try it.
Next step
Drill the patterns in the practice area. Then read about reported speech and tense consistency. Our proofreading guide shows how to check tenses in your own essays.