I want to ask about Grammar

[Rain$Windy]

Dear friend,

Would you tell me:can/could and be able to..How can use together.Thank you.Please give example

Rain

[Casiopea]

Click here.

[Rain$Windy]

Click here.

Dear friend,

what you mean?You want to ask about Grammar--why?I guess your Grammar is good

Rain

[Noego]

The link Cas has provided contains information about your question:

Click it and try to understand what is written. If you don't understand, write down some questions and come back here to ask them.

Best of luck