1. I an tired so i can't cycle to work
=> if I wasn't tired, I could cycle to work
2. that house is too expensive , so I can't buy it
=>If that house was cheap, I could buy it
3.Because he didn't work hard last term , he lost his job
=> if he had worked hard last term, he would have lost his job
4.It was cold yesterday , so I didn't not go for a walk
=> If It hadn't been cold yesterday, I would have gone for a walk
5. Mary didn't have money with her , so she couldn't buy that present
=>If Mary had had money with her, she could have bought that present
6.there was a test yesterday.you didn't know that , so you didn't study.
=>if i had known that , I would have studied for it
7 . the building is too high,so he can't climb up
=> If the building was short, he could climb up