1. CONDITIONAL SENTENCES
Type 0 - Type 1 - Type 2 - Type 3
Mixed Conditionals
Sentence connectors showing condition

2. Type 0 (general truths)
They are used to express something which is always true.
We can use WHEN instead of IF.
If-clause:
Present simple
Main clause:
If/When it SNOWS, the roads GET slippery and dangerous.

3. imperative, can/may/might/ must/should/could
Type 1 (real present)
They are used to express real or very probable situations in the present or future.
They are also used to give instructions.
If-clause:
present simple
Main clause:
future,
imperative, can/may/might/ must/should/could
If they WORK hard, they WILL FINISH the project on time.
If they FINISH the project, CALL me.
If they WORK hard, they MAY FINISH the project by next Friday.

4. Would/could/might + bare infinitive
Type 2 (unreal present)
They are 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 DIDN’T HAVE to work so much, I WOULDN’T BE so tired.
If-clause:
Past simple
Main clause:
Would/could/might + bare infinitive
If the weather WERE better,
we COULD / MIGHT HAVE a picnic.

5. Would/could/might + have + past participle
Type 3 (unreal past)
They are used to express situations which are contrary to facts in the past.
They are also used to express regrets or criticism.
If-clause:
Past perfect
Main clause:
Would/could/might + have + past participle
If he HAD BEEN more careful,
he WOULDN’T HAVE MADE such a big mistake.
If you HADN’T HAD a lot of luck, you COULD/MIGHT HAVE LOST all your money.

6. MIXED CONDITIONALS
Type 2 – Type 3
We can form mixed conditionals, if the context permits it, by combining an if-clause from one type with a main clause from another.
The most common types are:
If you WERE more sensible, you WOULDN’T HAVE SPOKEN to your parents like that.
Type 3 – Type 2
If he HADN’T STOLEN all that money, he WOULDN’T BE in prison now.

7. OTHER WAYS OF SAYING “IF”
EXAMPLES
AS LONG AS
We’ll go up to the mountains this weekend AS LONG AS the weather is OK.
PROVIDED/PROVIDING (THAT)
You can have a pet PROVIDED/PROVIDING THAT you look after it properly.
ON CONDITION (THAT)
You can have a pet ON CONDITION THAT you look after it properly.
SUPPOSE/SUPPOSING
SUPPOSE/SUPPOSING the price of oil tripled tomorrow, what would happen?
BUT FOR + noun
BUT FOR your help, I wouldn’t have done it.
OTHERWISE
You should have your air conditioned serviced. OTHERWISE, you will waste a lot of energy.
UNLESS
UNLESS governments act now, the environment will suffer.
IN CASE
IN CASE OF + noun
Take a coat with you IN CASE the weather gets worse.
IN CASE OF fire, leave the building immediately.