The baby didn't cry, so we had a good sleep.
If the baby had cried, we wouldn't have had a good sleep.
You didn't know how unpopular Jason was when you invited him to your party.
If I'd/I had known how unpopular Jason was, I wouldn't have invited him (to my party).
I'm afraid of spider. I can't pick it up.
If I wasn't/weren't afraid of spiders, I would pick it up.
You may want a chat, so just give me a ring.
If you want a chat, just give me a ring.
Throw a stone into water and it sinks.
If you throw a stone into water, it sinks, OR it'll/it will sink.
You haven't got a pen, so you can't write down the address.
If I had a pen, I could write down the address.
I haven't got a key, so I can't get in
If I had a key, I could get in.
It won't rain tomorrow and I'll go to the coast.
I’ll go to the coast tomorrow unless it rains. OR I’ll go to the coast tomorrow if it doesn't rain.
Warn your friend not to put too many tins into the plastic bag or it'll break.
If you put too many tins into the plastic bag, it'll break.
Nigel hasn't got satellite TV, so he can't watch the game.
If Nigel had satellite TV, he could watch/would be able to watch the game.
He's very ill so he isn't at work.
If he wasn't/werent very ill, he would be at work. OR Unless he was very ill, he would be at work.
You think Emma should book a seat on the train. Otherwise, she has to stand.
If Emma doesn't book a seat on the train, she'll have to stand.
Your friend might need some help. If so, tell her to give you a ring.
If you need some/any help, give me a ring.