You have 4
Although one is only considered half conditional, because it's something that'll happen for sure:

zero: If the sun comes out, the birds sing (certain)
first: If the sun comes out, I'll visit you (almost certain)
second: If I were a richman, I would buy a car (possible, but unlikely)
third: If I had been born rich, I would have had an helicopter (impossible)
(Aberracion Life's getting very complicated, but a lot of fun., Mon 6 Sep 2010, 10:47, 1 reply, 16 years ago)

Ah I see, that's a bit like open and closed in Greek
Open is possible, closed is unlikely (also known as remote)

Of course you can have mixed, but I think that's only mixed tenses not mixed type. Shit I need to brush up on my Greek :(
( Lampito rise with the moon, go to bed with the sun, Mon 6 Sep 2010, 10:48, Reply)

I don't think you can mix much in English
You can change If for When sometimes, though.
(Aberracion Life's getting very complicated, but a lot of fun., Mon 6 Sep 2010, 10:49, Reply)