Conditional sentences are sentences in which one thing depends upon another.

If I win the lottery then I will give all the money to charity.

We often leave out the word 'then'.

If I win the lottery, I will give all the money to charity.

There are different types of conditional sentence.

1) Things that might actually happen:

If it snows, we will build a snowman.

This type of sentence uses the future tense ('we will').

2) Imaginary things or things that might possibly happen but are unlikely:

If David Beckham came to our school, I would be very excited.

This type of sentence uses words like 'could' and 'would'.

3) Things that cannot be changed because they are in the past:

If I had worked harder, I would have passed the test.

This type of sentence uses words like 'could have' and 'would have'.

This is a bit of a tricky topic, so feel free to look back at this introduction at any point by clicking on the red help button on the screen.