✦ Lesson 2 · Grammar 1
The zero conditional
We use the zero conditional for things that are always true: facts, nature and habits. We use if or when and the present simple in both parts.
if / when + present simple, present simple
With a comma
If it's sunny, she takes an umbrella. (if first → comma)
Without a comma
She takes an umbrella if it's sunny. (if second → no comma)
⚠️ Careful!
We use the present, not the future: If it rains, I wear wellies ✔ — not If it will rain. With he / she / it the verb has an -s: When it rains, the plants grow.