We use the conditional Type 1 when we want to talk about situations we believe are real or possible in the future. 'If I study hard, I'll pass the exam.'
Type 2 conditional sentences talk about situations that are hypothetical. There is a possibility that the condition will be fulfilled.
'If you don't eat or drink, you die'. 'If you heat water, it boils'. Zero conditional is used to talk about facts or situations which are always true.
Conditional III indicates an impossible, hypothetical and unreal condition in the past and its probable result in the past. To learn about them, start reading!
Sometimes the two parts of a conditional sentence refer to different times. This is called a mixed conditional. Ready to learn?