why the if conditional seems hard for some students ,try the following and tell where the problem areas are.
Conditionals Exercises
1: If he comes,…………..
we will go to lunch.
we would go to lunch.
we would go to lunch

2: I would buy a new house………….
if I have a lot of money.
if I win the lottery.
if I inherited a million dollars.

3: If she misses the bus,…………………
I take her to school by car.
I would take her to school by car.
she have to walk.

4: If I had known you were in town,…………………
I would buy you some flowers!
I would have bought you some flowers.
I will buy you some flowers.

5: If he studies a lot,…………………
he might pass the exam.
he would pass the exam.
he is going to pass the exam.

6: I would get a new job…………………..
if I was you.
if I am you.
if I were you.
 
7: He will surely fail his exams…………………
if he not work harder.
unless he begins to study.
if he weren't serious.

8: She would live in New York now………………..
if she stays.
if she had stayed.
if she was to stay.

9: They would have bought that new car……………………….
if they had had the money.
if they had the money.
if they were having the money.

10: I leave on Saturdays………………………..
if she will come to visit.
if she comes to visit.
if she won't come to visit.

11: If he were rich,………………………………
he would help the poor more.
he will help the poor more.
he would have helped the poor more

12: If they had had enough good sense,…………………..
they would have moved to Helwan.
they would had moved to Helwan
they will move to Santa Helwan.

13: She will go crazy………………………………….
if you leaves her.
unless she leaves you.
if she don't leave you.

14: If this storm gets worse,…………………………………
we will have to go inland.
we have to get inland.
we must to go inland.

15: Watch out! If you touch that cable,………………………..
you will get a shock.
you shocked.
you had a shock.

16: I might have had time………………………………………
if you needed my help.
if you had asked me for help.
if you ask me for help.

17: I'm afraid I can't understand you………………………….
if you speak unclear.
unless you speak more clearly.
if you don't speak clear.

18: She would have gone…………………………………………..
if she had been in your position.
if she were in your position.
if she was in your position

19: You would certainly have been angry…………………………
if you discovered what he knew.
if you had discovered what he knew.
if you had discovered what he had known.

20: We'll have to walk if we…………………………………
run out of gas.
are going to run out of gas.
ran out of gas.

21: If someone offered to buy you one,……………………………….
which one do you choose?
which one would you choose?
which one had you chosen?