There are three types of conditional sentences in English: 1) First conditional - Used to refer to present or future situations that are possible or real. It uses the structure "if + present tense, will/present tense". 2) Second conditional - Used for unlikely, improbable, or hypothetical present or future situations. It uses the structure "if + past tense, would + infinitive". 3) Third conditional - Used for hypothetical or unlikely past situations. It uses the structure "if + past perfect, would have + past participle". The tenses are used to indicate the likelihood or time frame of the condition.

1. Conditional sentences We use conditional sentences to describe how an action or situation affects its result. Second Conditional First Conditional 3 Types of Conditionals Third Conditional

2. Conditional sentences contain an if-clause and a main clause. If I have enough money, conditional clause Examples : I will go to US. main clause I will go to U.S. main clause if I have enough money. conditional clause

4. We do not normally use will or would in the conditional clause, only in the main clause. 2. If + Past Tense 3. If + Past Perfect Tense would + infinitive would have + past participle e .g. If I knew her name, I would tell you . e .g. If I had won the lottery, I would have bought a new house.

8. For the second conditional, were replaces was If I were a rich man, I would stop working as a clerk. If I were to lose my job, I wouldn't be able to pay for my dream car.

9. Instead of if not , we can use unless . “ if ” + negative action = “unless” + positive action The meaning of both sentences is the same, but the action after ‘unless’ (close) is the opposite of the action after ‘if’ (don’t close). Compare: Your bird will fly away if you don’t close the window . Your bird will fly away unless you close the window.