This post fills a gap.

If you build it, they will come.

If it's raining, (then) I can't go.

If we were warriors, we wouldn't have done that.
but we're not, and we did

If I were Clan Leader . . .
but I'm not

If you had helped me, I wouldn't be going to Washington next week.
but you didn't, and I am

If you had given me that kind of food, I would be strong today.
(but you didn't, and I'm not)

If I were you . . .

If I were hunting right now . . .
but I'm not

If you had loved me, I would have been so happy.
(but you didn't, and I wasn't)

If you loved me, I would be so happy.
(but you don't, and I'm not)

If it rained tomorrow, they'd do a dance.
(but it won't, and they won't)

If it were raining, (then) I couldn't go.