What is the difference between cant and couldnt

In the above instance, "I couldn't do it" refers to an implied action that the person claims would be hypothetically impossible for them to carry out in the future. This is an example of a type 2 future conditional , involving the use of a modal.

Sure thing! Tom can't be moving the furniture upstairs - he's at work right now. Tom couldn't be moving the furniture upstairs - he's at work right now. They all refer to uncertain possibility at present or in the future. However, could in this sense can only be used in the positives and questions, not in the negatives.

The word "can't" refers to a definite impossibility in the present tense. However, the word "couldn't" refers to a impossibility in the past. In this case, it is correct to say "That can't be Obama at the door, it's too early. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams?

Learn more. Ask Question. Asked 7 years ago. Active 9 months ago. Your email address will not be published. Newer Comments ». Leave a Reply Cancel reply Your email address will not be published. Footer Join our email list and receive exclusive English guides. Ambiguity through colloquialism If we get into spoken English and investigate hypothetical conditions, could and can are often treated as completely ambiguous and interchangeable so be careful.

That is to say, they could mean: ' am unable to Only loosely connected and hardly worth mentioning only worth mentioning here to get a more complete list , examples follow: If my duck hadn't been strutting, it would no have been eaten. If your daughter has been calling my son, we need to change our number. When my wife is working, I might eat poorly. If Drake will be racing his hotrod, we'll all be in attendance.

This is my best guess as to why this transformation drill is so useful for adapting unreal language: With extremely rare exception, modals don't change form when put into the future tense: we can say there are no "future tense" modals or there are no present-tense modals if you find that more convenient. Implications I wanted to add this important section. Upman Bird Upman Bird 11 3 3 bronze badges. This doesn't deserve a thumbs down. It's misleading because these statements are true and easily veritable.

It's a good answer, I'm not sure why you were downvoted. Yeah, now I can't even edit my question because I'm under-rep. Also, the other answer is wrong. So, it shouldn't even be selected as a correct answer.

I'll just have my son edit it. You missed the part where I said that in this case it wasn't being used in its preterite sense. It may have been. That's literary criticism. Show 4 more comments. Sign up or log in Sign up using Google. Sign up using Facebook. I do not have any clues how they are used. Are they having Do they have slightly different meanings or they are are they just used for sentence variety? For variety. There is not much difference between may and might. I see may more often in academic papers and I hear might more often in ordinary conversations.

So may is slightly more formal, but its meaning is the same as might. In the examples in the conversation you quote above, both mean "It is possible that The only case to note carefully in that conversation is "I thought she might be with you".

After a verb in the past I thought that, You knew that, She said that, Answer this Question. Logic And Negative Sentences?