zero conditional

condition

• if / when + present simple - example: if it rains, the ground gets wet.

result

• present simple - example: water boils at 100 degrees celsius.

use

• when the result of a condition is certain and / or inevitable - example: if you heat ice, it melts.
• a scientific truth - example: when you mix red and blue, you get purple.

first conditional

condition

• if +present simple - example: if it rains tomorrow, we will stay indoors.

result

• will / won't + base form (or other future forms) - example: if it snows, i won't go to work.

use

• a real situation or event and its possible future consequences - example: if he studies hard, he will pass the exam.
• to give warning or make promises - example: if you don't finish your homework, you won't watch tv.

condition

if or when, unless, as soon as, before, after, until / till + present simple - example:

• when i finish this exercise.
• unless you give me his address,
• after we talk to her,
• until they know all the details about the journey.

result

will / won't + base form (or other future forms) - example:

• i will reward myself with a break.
• i won't be able to send the invitation.
• i will update you on the progress.
• we won't make any reservations.