If I ( ) a bird, I could fly in the sky.

As I am not a bird, I cannot fly.

If you ( ) me a car, I could have driven her home.

As you didn't buy me a car, I couldn't drive her home.

If she ( ) honest, I would have accted her propoal.

But she wasn't, so I rejected her proposal.

If she ( ) honest, I would accept her proposal.

She had better be honest.

If Julie ( ) a daughter, she could have understood me. (have)

As she didn't have a daughter, she couldn't understand me in the past.

If Julie ( ) a daughter, she could understand me.

As she doesn't have a daughter, she cannot understand me.