Zero & First Conditional

It is used when the result will always happen. (I'm talking in general, not about one particular situation.) The result of the 'if clause' is always the main clause.

 If water reaches 100 degrees, it boils. (It is always true, there can't be a different result sometimes).

If I eat peanuts, I am sick. (This is true only for me, maybe, not for everyone, but it's still true that I'm sick every time I eat peanuts)

[If + present] + [present]100% – will always happen.

You get water if you mix hydrogen and oxygen.

Snakes bite if they are scared.

If babies are hungry, they cry

>>> Identify the condition & the result.

*be careful with the commas

It's used to talk about things which might happen in the future. Of course, we can't know what will happen in the future, but this describes possible things, which could easily come true. PROBABLY but not CERTAIN.

 If you don't eat now, you'll be hungry later. If she doesn't call, I'll be annoyed. (It is possible, 50% you may not feel hungry).

If she doesn't call, I'll be annoyed. (Probably he calls you are not sure 100%)

If + present tense, (comma) + future with “will” 

[condition]                 [result]

OR

future with “will”  (no comma) + if + present tense

[result]                     [condition]

If I have enough money, I'll buy some new shoes.

She'll be late if the train is delayed.

>>> Identify the condition & the result.

*be careful with the commas