Conditional clauses express a condition – something which must happen first so that something else can happen. Can you use conditional clauses correctly? Test your knowledge with this grammar exercise.
Fill in the blanks.
1If I ............... you, I wouldn't do this.
Select 2 answers.
Wrong!
"Were" and "was" are both acceptable here, but "were" is more standard in this second conditional advice sentence.
2If you ............... blue and yellow, you get green.
Wrong!
"Mix" is correct because zero conditional sentences use the present simple for general facts.
3If I had known the answer, I ............... you.
Wrong!
"Would have told" is correct because the third conditional uses would have plus the past participle.
4Unless you start now, you ............... late.
Wrong!
"Will be" is correct because a real future result follows the present simple after unless.
5If I were you, I ............... that again.
Wrong!
"Would never do" is correct because this second conditional gives advice about a possible action now or in the future.
6Provided that you ............... there half an hour earlier, you will be able to get straight in.
Wrong!
"Get" is correct because provided that is followed by the present simple in this first conditional sentence.
7Unless you ............... smoking, you will develop serious health problems.
Wrong!
"Stop" is correct because unless takes the present simple for a real future condition.
8If I had been there, I ............... this from happening.
Wrong!
"Would have prevented" is correct because the third conditional uses would have plus the past participle.
9If you ............... hurry, you will miss the flight.
Wrong!
"Do not" is correct because the first conditional uses the present simple in the if-clause.
10If the weather permits, we ............... again.
Wrong!
"Will meet" is correct because this sentence talks about a real future possibility.
11If I ..............., I will come tomorrow.
Wrong!
"Can" is correct because the condition means if it is possible tomorrow.
12............... you come tomorrow if you can?
Wrong!
"Will" is correct because the question asks about a real future possibility.
Done.
Score: 0/12
Answers
- If I were / was you, I wouldn’t do this.
- If you mix blue and yellow, you get green.
- If I had known the answer, I would have told you.
- Unless you start now, you will be late.
- If I were you, I would never do that again.
- Provided that you get there half an hour earlier, you will be able to get straight in.
- Unless you stop smoking, you will develop serious health problems.
- If I had been there, I would have prevented this from happening.
- If you do not hurry, you will miss the flight.
- If the weather permits, we will meet again.
- If I can, I will come tomorrow.
- Will you come tomorrow if you can?

