Unless...

Or...

In case...

We use Unless, in case and Or in sentences which are kinds of first conditional.

• If it rains tomorrow, I won’t go to the circus.

Unless – if + negative

• You will miss your train, if you don’t hurry.• You will miss your train unless you hurry.

• You won’t get paid, if you don’t call your boss.• You won’t get paid unless you call your boss.

• He won’t know the truth, if you don’t tell it to him.• He won’t know the truth unless you tell it to him.

In case – if + present (imperative)

• If you need help, call me.• Call me, in case you need help.

• Take your umbrella because it might rain.• Take your umbrella in case it rains.

• You can take the money, if you need.• You can take the money in case you need it.

Or – join 2 similar things; in a conditional sentence, the imperative is similar to the... Future clause.

• Be careful. If you aren’t carefull, you’ll hurt yourself.

• Be carefull or you’ll hurt yourself.

• Bring your torch, so that you can see in the dark.• Bring your torch or you won’t be able to se in

the dark.

Future .............unless + present simple

Imperative.........in case + present simple

Imperative...................or + future