Hi all,

My name is Joon

I have a question about can/may distinctions in the 'possibility' sense

Here is what my grammar book says about the distinctions:

'May' represents 'factual possibility' and 'can' represents 'theoretical possibility'

The difference is clarified by these set of equivalent statements:

(A) Factual: The road may be blocked=It is possible that the road is blocked

(B) Theoretical: The road can be blocked=It is possible for the road to be blocked

'may' is paraphrased by It is possibled followed by a that clause, but 'can' is paraphrased by It is possible followed by a (for+Noun phrase+)to infinitive construction.

The second sentence (B) describes a theoretically conceivable happening whereas the first feels more immediate, because the actual likelihood of an event's taking place is being considered.

Ok, my question is:

What is the difference in meaning between the following sentences?

A: We may see you tomorrow

B: We can see you tomorrow

The author of my grammar book says, "'can' could not replace may without a considerable change in meaning", but he doesn't go on to explain the difference in meaning at all.

I kind of doubt, in the first place, if the second sentence can be paraphrased as the following:

We can see you tomorrow=It is possible for us to see you tomorrow or It will be possible for us to see you tomorrow(???)

The sentence refers to one possble(actual) event, which does not fit the description of 'theoretical possibility.

And likewise I don't uderstand why 'can' is used in the following sentences.

A: Can you come over for dinner tonight?

B: Yes, I can come over for dinner tonight.

I can come over for dinner tonight=It is possible for me to come over for dinner tonight(??)

Could anyone help me with this? I would really appreciate it.
Anonymous(A) Factual: The road may be blocked=It is possible that the road is blocked
(B) Theoretical: The road can be blocked=It is possible for the road to be blocked
May:

Let's not take that route. The bridge may be closed. ( I think about the possibility of driving to the bridge and finding that the way is blocked.)

The highway department may close that bridge whenever it is dangerous. (It has the authority from the mayor to do so.)

Can:

The highway department can close that bridge whenever it is dangerous. (The highway department has the ability to do so - they have the proper barricades and signs.)

A: We may see you tomorrow. (We are both going to the same place, and there is a possibility that we will meet each other. May has the same sense as might..)

B: We can see you tomorrow. (We have free time, and are willing to meet you tomorrow. We can't see you tomorrow. How about next Monday?)

A: Can you come over for dinner tonight? (This asks if you are free and do not have another engagement.)

B: Yes, I can come over for dinner tonight. (You agree to come for dinner.)
AnonymousWhat is the difference in meaning between the following sentences?
A: We may see you tomorrow
B: We can see you tomorrow
A: It is logically possible that we will see you tomorrow. Who knows what may happen? Maybe we will see you; maybe we won't see you. We will have to wait and see what happens tomorrow. It depends on where you are and where we are tomorrow.

B. Our schedule is such that we have the ability to meet with you tomorrow. We are not so busy that we will be unable to meet with you. We are certainly able to arrange a meeting with you. We are free to meet with you tomorrow. We have no other obligations that would prevent us from meeting with you tomorrow.

AnonymousWe can see you tomorrow=It is possible for us to see you tomorrow or It will be possible for us to see you tomorrow ...
I can come over for dinner tonight=It is possible for me to come over for dinner tonightYes. These are accurate paraphrases.

AnonymousI don't uderstand why 'can' is used in the following sentences.
A: Can you come over for dinner tonight?
B: Yes, I can come over for dinner tonight.
A: Are you free from other obligations tonight? Are you able to schedule dinner with us?
B: Yes. There is nothing else that I have to do at that time. I am able to schedule that.

One meaning of "can do something" is "free to do that thing", "not obligated to do something else".

CJ
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Thank you for taking the time to answer my question.

It is now very clear what the difference in meaning between the two is.

It really helped!
Thank you for answering my question!

It is really difficulf for non-native English speakers to understand these concetps and your answer definitely clarified the ambiguities. Thanks!