You are welcome to answer questions posted in the Ask a Teacher forum as long as your suggestions, help, and advice reflect a good understanding of the English language. If you are not a teacher, you will need to state that clearly at the top of your post. Please note, all posts are moderated by our in-house language experts, so make sure your suggestions, help, and advice house the kind of information an international language teacher would offer. If not, and your posts do not contribute to the topic in a positive way, they will be subject to deletion.
This is a big area. If we are talking about ability, then can is present and could past. If we are talking about a poissibility, then can is more likely than could and could have refers to a possibility in the past.
thanks Mr Tdol
but...i heard some people use "could" when there is a possiblity of something in future....can we use either i mean "can" or "could" or it depends on the sentence...plz remove my confusion.
I can come tomorrow- I am certain of this
I could come tomorrow- This means that it is possible if you agree, so it is less certain than 'can', less definite
It could rain tomorrow- this isn't certain, but there's a chance of rain.
You're welcome, Gulrina. With these modal verbs (can, could, will, etc), the past tense is often used to talk about the future- past tense does not necessarily mean past time, and with the modals, it usually doesn't.
may i know??? 
Linear Mode
