The Zero conditional

If + subject + present simple , subject + present simple

. This case is used for situations that are always true (laws of nature, physics, astronomy, etc.

تعبر عن حقائق ثابتة مثل قوانين الطبيعة والفيزياء والفلك الخ ….

☺ If water is heated to 100c, it boils.  

☺ If the moon passes between the sun and the Earth, there is a solar eclipse.

كما أنها تعبر عن عادات ثابتة

☺ If I feel tired, I usually go to bed.      If = When

Rewrite:

1. Heat changes water into steam. (If)

2. The body dies due to the stop of the brain. (if)

3. Not getting enough water, plants die. (If)