I won't sleep
If I have a headache,
If the telephone rings,
If he doesn't read the map,
If the computer doesn't work,
If it isn't sunny tomorrow,
If it doesn't rain,
If you send the letter today,
we will go to the beach.
he will get lost.
I will take an aspirin.
it will arrive tomorrow.
the picnic will be cancelled.
I will call a technician.
if I drink coffee.
do not answer it.