Can you tell me the difference between "Can" and "Able"?
X: I am not able to decide.
O: I can't decide.
X: We aren't able to stop laughing.
O: We can't stop laughing.
With verbs of perception (e.g. see, hear, smell) and verbs of the mind (e.g. understand, decide, remember) we usually use can, can't, etc: "I can't hear you. Could you speak louder please?" "I think I can smell something burning" "I can see why she doesn't like her boss"
X: In some countries you are not able to drink alcohol until you are 21.
O: In some countries you can't drink alcohol until you are 21.
For actions that are controlled by laws or rules use can, can't, etc. or be (not) able to.
Here is a video to help you remember: https://www.youtube.com/watch?v=mQnADsIpSqg&t=27s
