Zero Conditional Sentences

Open Conditionals

In this type of conditional sentences we can use many different tenses.

If you are right, I am wrong. - In the if-clause and the main clause we use present tense.

If the ground is dry, don't forget to water our plants. - In the main clause we have used the imperative.

If you should be passing, come and see me. - We express here something depending on chance.

If you get this right, I shall have answered every question correctly. - We have used here Future Perfect Tense.

If you should meet him, tell him I must see him.

All the above sentences are open conditions. The speaker doesn't know whether the condition is or isn't the effect.

If I said this, I apologize.

If I made a mistake, I will try to remedy it.

If I have made a mistake, I will try to remedy it.

You have the same tense in both clauses: in the if-clause and the main clause.

If you take a raisin and soak it, it swells. It always happens like that.

If the wind blows from the north, this room is very cold.

If / When the wind blew from the north, we moved to the other room.

If / When the weather is fine, we have our meal on the porch.

If you never have a cold, you are very lucky. - We cannot use here 'when'!