Zero and 1st Conditional

Conditional sentences have two parts: the if-clause describes a possible event and the main clause describes the result of that event.

The if-clause can come before or after the main clause.

When the if-clause is first, put a comma between the two parts ex:

If the lizard gets scared, it hides.

The lizard hides if it gets scared.

The zero conditional describes events and results that happen regularly or are always true.

If and when both mean ‘every time’: every time the event happens, the same result happens.

We use a present tense in both the if-clause and the main clause ex:

• when the lizard gets scared, it hides.
• If I go to the city center, I always eat in that restaurant.
• Anyone can succeed if they work hard.

The first conditional describes possible future events and the expected results of those events.

We use a present tense in the if-clause and a future form in the main clause ex:

• If the scientists succeed, many people will live longer.
• If I don't work hard, I won't be successful.
• Will you have to commute if you get the job?
• He’ll cook you an amazing meal if you ask him to.

Imperative conditionals

We can use imperatives in the main clause. The meaning can be present or future ex:

• If you're tired (now), go to bed (now).
• If you’re tired when you arrive (this evening), go to bed (then).

Unless

Unless means ‘if not’.

We can use it in zero or first conditionals and with imperatives ex:

• We play every Saturday unless it rains.
• It won’t hurt you unless you run away.
• I will come to your house unless it rains.

In general, don’t use a future form (e.g. will, going to) in the if-clause (or after when or unless) ex:

If the government changes the law, this area will become a national park.

NOT If the government will change the law ....