I could, but I have a very important meeting to go to

[NAL123]

Consider these sentences of mine, please:

Person A: Can you come shopping with me this evening?
1) Person B: I could, but I have a very important meeting to go to. So, sorry, I can't.
2) Person B: I might, but I have a meeting to go to. So I'm not sure.

Is the use of "could" and "might" correct in person B's responses (1) and (2)?

 

[emsr2d2]

#1 doesn't work at all. Using "could" indicates that it is possible for you to go shopping with A. The end of the sentence says you can't. For that one, open with something like "I would have loved to but ..." or "I would if I could". If you opt for the latter, I'd change the word order to "I would if I could but I can't! I've got a meeting this evening".

#2 would be OK if you added "be able to" after "might". Also, as we frequently advise learners here, don't start a sentence with "so". Remove the full stop after "go to" and simply continue the sentence with "so I'm not sure".

 

[NAL123]

#1 doesn't work at all. Using "could" indicates that it is possible for you to go shopping with A. The end of the sentence says you can't.

So #1, with "could", is as meaningless as the following sentence, with "can":

Person B: I can, but I have a very important meeting to go to. So, sorry, I can't.

In other words, there's not much difference between the meanings of "could" and "can" here. Am I right?

 

[jutfrank]

So #1, with "could", is as meaningless as the following sentence, with "can":

You don't need to compare levels of meaninglessness.

Your sentence #1 doesn't make sense because with could, the speaker is saying that there is a possibilty, and then with can't he's saying that there isn't a possibilty. It's contradictory.

Person B: I can, but I have a very important meeting to go to. So, sorry, I can't.

Also contradictory. I don't think you need to compare degrees of contradictoriness. Get the simple logic right first.

In other words, there's not much difference between the meanings of "could" and "can" here. Am I right?

This context aside, these two modal verbs express different kinds of possibilty, and this is what you should focus on. Forget about this particular example sentence—it's incoherent.

Sorry, I can't.

This bit is good. It expresses that going shopping is not possible because the speaker is unavailable.

 

[emsr2d2]

So #1, with "could", is as meaningless as the following sentence, with "can":

Person B: I can, but I have a very important meeting to go to. So, sorry, I can't.

Do you really need us to tell you that saying "I can go shopping with you this evening but I can't" is meaningless?

 

[NAL123]

One last question:

#2 would be OK if you added "be able to" after "might".

2) Person B: I might be able to, but I have a meeting to go to so I'm not sure.

Now, although I can't say sentence (1) in post #1, can I say the following:

3) Person B: I could, but I have a meeting to go to so I'm not sure.

If so, is there any difference between (2) and (3) above?

 

[jutfrank]

can I say the following:

3) Person B: I could, but I have a meeting to go to so I'm not sure.

No.

If so, is there any difference between (2) and (3) above?

Yes, the sentence meaning is different. These are two different kinds of possibility. In my own language, 'might' is for real possibility and could is for 'theoretical' possibility. Since the speaker is thinking of a real possibility, about a real situation that she's probably going to act upon, she uses 'might'. Using 'could' would be purely theoretical, such that going shopping is merely a logically possible option.

 

[emsr2d2]

3) Person B: I could, but I have a meeting to go to so I'm not sure.

I find that very unlikely. I still say that using "could" there makes no sense because you're not sure you can. I also find the use of "could" and "I'm not sure" incongruous.

I would be able to if I didn't have a meeting. (You definitely can't go.)
I wish I could but I've got a meeting. (You definitely can't go.)
I'm not sure. I've got a meeting and I don't know if it'll finish in time. (This is closer to your #3.)

 

[NAL123]

I would be able to if I didn't have a meeting. (You definitely can't go.)
I wish I could but I've got a meeting. (You definitely can't go.)

What about these:

1) I would be able to but I've got a meeting.
2) I could if I didn't have a meeting.
3) I could were it not for the fact that I have a meeting to go to.

Do they also mean I definitely can't go?