We use the zero conditional to talk about things that are always true
- If you heat water, it boils.
- When the sun goes down, it gets dark.
- It lights up if you push that button.
The present simple is used in both clauses
Now we are going to work in pairs
IF CLAUSE - if + present simple
MAIN CLAUSE - Present simple
- If I oversleep, I miss the bus
- If I miss the bus, I am late for school
- If I am late for school, my teacher gets angry
The consequence can be expressed before or after thE condition
- If you come to Canada, we can visit Vancouver
- We can visit Vancouver if you come to Canada
Note: If the condition comes first, a comma is used. If the consequence come first, no comma is used