Dave's ESL Cafe's Student Discussion Forums

[Yukihide]

Qustion 1
Is it correct that the word "could" meaning the past tense can be used only if the sentence specifies the past tense clearly like "I could do this yesterday. " ?

Question 2
Suppose the above is correct. It is laso said that "could not" meaning the past tence can be used even the sentence does not clearly secifies the tense. If so, does "could not" always mean the past tense ? Can't I use the sentence "You couldn't do this" if I would like to expres my feelling that "You will not be able to do this."

Best wishes

Yukihide

[lotus]

Hi Yukihide,

Qustion 1
Is it correct that the word "could" meaning the past tense can be used only if the sentence specifies the past tense clearly like "I could do this yesterday. " ?

It should be "I could have done that yesterday", or "This could have been done yesterday."

"Could" means being able to do something conditionally in the past, present or future.

I could have done that (past)
I could do this now (present)
I could do this if that happens (looking into the future)


Question 2
Suppose the above is correct. It is laso said that "could not" meaning the past tence can be used even the sentence does not clearly secifies the tense. If so, does "could not" always mean the past tense ? Can't I use the sentence "You couldn't do this" if I would like to expres my feelling that "You will not be able to do this."

You could'nt do this - usually means you can't do something because you lack a skill.

You will not be able to do this - usually means you will not be able to do something because factors outside of your control.


-- lotus

[Yukihide]

Hi Lotus,

Thank you very much for your comment.

So is it incorrect to say the following?

1) I could do this yesterday.
2) I could not do this yesterday.
3) I could not do this yesterday. ( The speaker is talking about yesterda.)

Regards,

Yukihide

[lotus]

Hi Yukihide,

So is it incorrect to say the following?

1) I could do this yesterday.
2) I could not do this yesterday.
3) I could not do this yesterday. ( The speaker is talking about yesterda.)

The sentences should read (I added "homework" to make it clearer):

1) I could have done this (homework) yesterday.
2) I could not have done this (homework) yesterday.
3) same as 2.

You might have noticed that you must include "have" when strictly speaking of the past.


--lotus