1. A few of our workers have been off sick. I'm sorry, but we won't be able to/can't finish the project
until the end of the month.
2. Sharks can/are able to sleep while they are swimming.
3. I used to be able to speak French, but now I've forgotten most of it.
4. My nephew could/was able to speak fluent English, Spanish and German when he was only six years old.
5. You will be able to/can make some fantastic cakes when you get back from that cookery course next month.