If I was thirsty, I would drink the lemonade.

If I had been thirsty, I would've drunk the lemonade.

If I would have been thirsty, I drank the lemonade.

If I had known Kirsty was in town, I would have called her.

I had called Kirsty if I had know she was in town.

I would had called Kirsty if I have known she was in town.

If I knew this documentary was important, I had watched it

If I would have known this documentary was important, I've watched it

If I had known this documentary was important, I would've watched it

I hadn't walked home from the disco if my friend wasn't too drunk to drive.

I wouldn't have walked home from the disco if my friend hadn't been too drunk to drive.

I wouldn't had walked home from the disco if my friend hadn't been too drunk to drive.

If I had known the store had closed at 6pm, I would've gone

If I knew the store would have closed at 6pm, I would've gone

I would've gone to the store if I know it had closed at 6pm

If I would have known the yogurt was yours, I wouldn't have eaten it

If I had known the yogurt was yours, I wouldn't have eaten it

I hadn't eaten the yogurt if I knew it was yours

If I had some breakfast, I wouldn't be hungry then.

If I would had had some breakfast, I wouldn't be hungry then.

If I had had some breakfast, I wouldn't have been hungry then.

If I saw Tom at the party, I would've spoken to him.

If I had seen Tom at the party, I would've spoken to him.

If I would have seen Tom at the party, I would've spoken to him.