'If" some thing happened

[endeavor6636]

what is the proper ways to use : if i "find"......i will
if i "found"....i would





i knew that when you imagine something would happen- you use past tense while you think something will possibly happen in the future- you use present
tense. but i still mix up both of them while writting a essay.

because sometime both of them seem alike.


ex: if i pass the exam (on this occasion what tense shall i use?)

-i am imagine that i would pass the exam(maybe i could, maybe not) but i also feel that it has the possibility to pass )

[Mister Micawber]

.
If I see you, I will kiss you. (I may see you, Endeavor)
If I saw you, I would kiss you. (I probably won't see you.)

If I pass the exam, I will buy you a drink. (I have a good chance of passing the exam)
If I passed the exam, I would buy you a drink. (I don't think I passed)
.