as I could do at college

[EngLearner]

Source: "Three Blind Mice", a movie (timestamp: 11m54s).

Abigail has taken a break from her studies at college because she's reliant on drugs, but that isn't helping her much and she can't stop taking them. Her mother is angry with her and wants her to admit that she has a problem. Abigail says to her mother:

Please, mom. Please. Just let me speak. This whole situation is an overreaction. And yes, I haven't been doing as well as I could do at college. But I'm working at figuring that out and fixing it.

Is it a past tense could as in "I could lift 100kg when I was 20.", or is it a hypothetical could that refers to the present/future as in "You could come here tomorrow if you like."?

 

[teechar]

Is it a past tense could

No.

, or is it a hypothetical could that refers to the present /future

Yes.

 

[EngLearner]

Source: "Silver Wolf", a movie (timestamp: 18m00s).

There's a song in the movie. It goes like this:

I saw you come around. You were by the lost and found. You had your secret smile. Tell me about it. You know it's not my cup of tea. Who knows, who knows, who knows how you could do this to me.

Is it a past tense could, i.e. who knows how you were able to do this to me?

 

[teechar]

What do you suspect it refers to?

 

[EngLearner]

What do you suspect it refers to?

There are these sentences that come before it:

I saw you come around. You were by the lost and found. You had your secret smile.

So I think it refers to the moment all of that happened. It's a past tense "could."

 

[teechar]

I think it's the same as "how could you do this to me?", in which case it's a rhetorical lament/reproach.

 

[jutfrank]

You should ask whether it's past meaning, not past tense (could is always past tense). Secondly, you want to know whether the meaning is ability or possibility.

No, it isn't about ability—it's about possibility. And no, the possibility is not past, either. Yes, the events are all past events but the possibility relates to a kind of general present time.

A further point: The use of the word this suggests to me that the speaker is thinking more in terms of the present than the past.

 

[EngLearner]

...who knows how you could do this to me.

Would it be correct to say that it means this: "...who knows how it would be possible for you to do this to me."?

 

[jutfrank]

I'd put it like this: How is it possible for you to do such a thing to me?

It doesn't matter that what you did was in past time. What matters is that you've proved the possibility of such action. That possibility doesn't exist in time, at least not in any kind of local time.