is this correct?

[Teia]

Hi teachers!

Is the following statement correct? I have read it in a grammar book.

"Could" cannot be used in positive sentences in which you describe a momentary or one-time ability.

Yesterday, I could lift the couch by myself. Not Correct

If the sentence above is not correct, how shall I say?

Yesterday, I was able to lift the couch by myself. - is it correct?

Thank you very much in advance.

 

[Raymott]

Hi teachers!

Is the following statement correct? I [STRIKE]have [/STRIKE]read it in a grammar book.

"Could" cannot be used in positive sentences in which you describe a momentary or one-time ability.

Yesterday, I could lift the couch by myself. Not Correct

Not necessarily. In the right context it's possible.
"I've been doing weight-lifting training. I test myself by seeing if I can lift the couch. Finally, yesterday, I could lift the couch by myself!" OR. "I must be getting weaker. Yesterday I could lift the couch by myself. Now I can't."

If the sentence above is not correct, how shall I say?

Yesterday, I was able to lift the couch by myself. - is it correct?
Yes, that's correct, and possibly more widely usable. You could use it in the above contexts, for example.

Thank you very much in advance.

R.