We use the 0 Conditional to talk cause and effect, and things that always happen or that are always true. For example, if you drink enough water, you are hydrated.
Notice the sentence structure:
If + Present Simple, Present Simple.
If there is too much rain, the river floods.
Present Simple if + Present Simple
The river floods if there is too much rain.
You can use ‘when’ instead of ‘if’ to mean the same thing.
When there isn’t enough rain, the crops die.
The crops die when there isn’t enough rain.
Review the Present Simple.
Can you match the 0 Conditional phrases to make sentences?
Let’s take turns asking and answering questions in the 0 conditional:
What usually happens if/when…
there is too much rain?
there isn’t enough rain?
a volcano erupts?
there is a huge snow storm in your area?
the streets are icy?
the power goes out in your home because of a storm?
a tornado strikes a populated area?
a water reservoir dries up?

