The conditional sentences are clauses introduced with IF, INCASE, UNLESS, WHEN, e tc.
There are four types of conditional sentences: Zero-conditional 1-st conditional 2-nd conditional 3-rd conditional
Zero-conditional Denotes general truths and laws of nature. If-clause Main clause If+ present simple present simpleZero-conditional sentences are used to express something which is always true.We can use when or whenever instead of IF: e.g. If/When it rains, the roads get slippery and dangerous.
1-st Conditional (real present) IF- Clause Main clauseIf+ present simple/ future / imperative / present cont./ present can, may, might, perfect / present perfect must, should, continuous could + bare infinitive It is used to express real or very probable situations in the present or future:e. g. If we work hard, we will finish the project on time.
2-nd Conditional (unreal present) If-clause Main clause If+past simple or would/could/ past continuous might…+bare infinitiveIt is used to express imaginary situations which are contrary to facts in the present and, therefore, are unlikely to happen in the present or future. They are also used to give advice.If I didnt have to work long hours, I wouldnt be so tired.
3-rd Conditional (unreal past) If — clause Main clause If+ past perfect / would/could/might+ past perfect continuous perfect bare infinitive They are used to express imaginary situations which are contrary to facts in the past. They are also used to express regrets or criticism.e. g. If I had been more careful, I wouldnt have made such a big mistake.
NB!We use IF to show that something might happen. We use WHEN to show that something will definitely happen.e. g. If Steve calls, tell him Ill be back in ten minutes (Steve might call). When Steve calls, tell him Ill be back in ten minutes (Steve is sure to call).
We can also form conditonals by using:Unless - Unless you help me, IProviding / provided that wont finish on time.So/as long as - Ill water the plantsOn conditon (that) providing/providedWhat if (that) I have time thisSuppose/supposing afternoon.Otherwise (=if not) - So / as long as youBut for promise to be back byOr (else) midnight, you can goEven if to the party.In case of / in the event of, etc.
We do not normally use will, would or shouldin an if-clause. However, we can use will or wouldafter IF to make a polite request or expressinsistence or uncertainty. We can use shouldafter if to talk about something which ispossible, but not very likely to happen. a) If you will wait for a minute, Mr Carringtonwill be able to see you.b) If Paul should turn up, tell him towait for me
We can form MIXED Conditionals if the contextpermits it, by combining an if-clause from one type with a main clause from another: Main clause If-clause Type 1 Type 2 she wont come to workIf she got back late last night, today. Type 2 Type 3 If you were more sensible, you wouldnt have spoken to your boss like that. Type 3 Type 2If she hadnt missed the bus, she would be here now.
WISHESWe use the verb wish «I wish I were a and the expression millionaire!» If only... to express a wish. If only is more emphatic than I wish. «If only I had more time!»
Wish / If only... + past simple / past continuousThis structure is used when we want to say that we would like something to be different in the present. I wish I were smarter...
Wish / if only + past perfectThis structure is used to express regret that something happened or did not happen in the past. I wish / If only I hadnt stolen the motorbike
Wish / if only + wouldThis structure is used:a) for a polite imperativeb) to express our desire for a change in a situation or someones behaviour. I wish you would be more attentive!