1. The receptionist gave me very useful information.
> The information was given to me by the receptionist
2. She teaches English at our school.
> She is  an English teacher  at our school.
3. I'm not good at cooking, so I can't become a chef.
> If i was good at cooking ,  I could become a chef.
4. You should ride your bike carefully, or you may have an accident.
> If you  don't ride your bike carefully, you may have an accident.