if i can  you can. 
if you eat you get fat.
if you talk i dont.
if you go i go.
If my sister does not eat dinner, she gets hungry at midnight. 
If I exercise, I look great!
If someone calls, take a message please. 
If you do not study, you learn nothing. 
If you eat too much, you get fat. 
If she wants to learn a musical instrument, she has to practise. 
If you cook dinner, I wash the dishes.. 
If the phone rings, I answer it. 
If the weather is sunny, we can go to the beach. 
If you do not feel well, go and see a doctor.
If you are late i wont wait for you
If I have enough money, I will buy this car. 
If it is sunny, we will go to the park
Peter will be sad if you leave. 
If we catch the next train, we will get there on time. 
If they get the letter in time, they willl be able to change their plans. 
What will you do if your boss refuses to give you a rise?
If we play well, we will win. 
If I rains, we will cancell the picnic.
You will be tired if you do a lot of exercises. 
If you do not feel well, you will have to see a doctor.