If we will not practice harder, we would not win.

If we don't practice harder, we will not win. 

if we didn't practice harder, we would not win. 

If the examinees were not late, they would pass.

If the examinees were not late, they would have passed.

If the examinees had not been late, they would have passed.

If he was not home, the kids would play outside.

If he is not home, the kids will play outside.

If he had not been home, the kids would have played outside.