Modal verbs in conditional sentences
Modal verbs can, could, might etc. can be used in all types of conditional sentences.
– I might send him an email if I can find his address.
– If she had someone to look after the children, she could go out to work.
– If they had told us about the danger, we might never have gone there.
Mixed conditionals
It is possible to have sentences that mix conditionals:
1. An if clause referring to the past with a main clause referring to the present or future.
– If I had invested in that company ten years ago, I would be rich now.
– If we hadn’t been given all that homework, we could go swimming.
2. An if clause referring to the present or future with a main clause reffering to the past.
– If you don’t like sweet things, you shouldn’t have ordered that dessert.
– If you‘ve got an exam tommorow, you ought to have started revising by now.
Polite expressions
1. would can be used after if in polite expressions.
– If you wouldn’t mind waiting here, I’ll find someone to look after you.
2. If + should is common in formal letters.
– If you should require any further information, please do not hesitate to contact us.
3. For even greater formality, if can be omitted, and should can begin the sentence.
– Should you wish to contact me, I can be reached at the above adress.