Examples:
If I finish my work,
I will get something to eat.
If I don't finish my work,
I will not get something to eat.
If she finishes her work,
she will get something to eat.
If she doesn't finish her work,
she will not get something to eat.
DUS
gebruik don't en doesn't
in de present simple bij ontkenning,
BEHALVE
bij het werkwoord am, is, are
If he is happy, she will be happy too.
If he isn't happy, she won't be happy.