It is able to be possible/ She is able to have drunk


If "can" and "be able to" are interchangable sometimes, for example:

She can speak Latin = She is able to speak Latin

Can "be able to" be used instead of "can" in:

She can't have drunk that much coffee = She isn't able to have drunk that much coffee

It can be possible that he has forgotten about us = It is able to be possible that he has forgotten about us ?

Michael Azarenko

Posted 2020-06-05T13:03:52.380

Reputation: 989

1"It is able to be possible" is not grammatical in English. You mean: It could be possible. – Lambie – 2020-06-05T15:30:25.150

I was told "It can be posible" was bad. How can "It could be possible" be okay? – Michael Azarenko – 2020-06-05T15:35:08.567

1There is no need to say: It can be possible. If it can be possible, it is possible. However, it would be possible is idiomatic, if you believed me. For the past tense re the coffee and can: She could have drunk that much coffee. could is the past of can. – Lambie – 2020-06-05T16:28:26.630

What if I am unsure whether it's possible? "It can be possible, I don't know" – Michael Azarenko – 2020-06-05T17:27:11.540

1No, it might be possible, I don't know. – Lambie – 2020-06-05T17:41:55.870

Why not "It may be possible, I don't know? – Michael Azarenko – 2020-06-05T17:52:16.393

1It may or might,but not can. – Lambie – 2020-06-05T18:10:41.030



The short answer is no. The exchanges don't work.

In some contexts you might turn She can't have drunk that much coffee (which is fine) into She isn't/wasn't able to have drunk that much coffee but it's an uncomfortable mouthful.

She wasn't able to.... is far more likely to be used in a context such as She wasn't able to reach the the fruit without using a ladder, referring to someone's physical limitations.

It can be possible that he has forgotten... is not idiomatic. People would simply say It is possible that he has forgotten....

Is able to be possible.... doesn't work at all. We don't generally use able after it. Creatures are able, organisations and governments are able. We even talk about machines and vehicles being able. But it isn't able unless we already know what it refers to. That's to say that you can't use a placeholder it, as in It is able to rain when you mean that it might rain.

Ronald Sole

Posted 2020-06-05T13:03:52.380

Reputation: 19 044


  • Why is "She wasn't able to have drunk that much coffee" okay but "She isn't able to have drunk that much coffee" bad? The difference is in the Tense only.

  • Let's change "possible" for 'true". 'It can be true that he has forgotten" - okay or bad?

  • So, if we talk about a homeless cat, we can't say "It is able to jump high:. If this cat is mine and I love him, speaking of him using "he", I can say "He is able to jump high", but the subject doesn't change - it's still the cat. Sometimes you say "it", sometimes "he".

  • < – Michael Azarenko – 2020-06-05T14:39:40.953


  • Both are possible, depending on context. 2. It's clumsy - not idiomatic. We don't talk that way. 3. Once you have made clear that it refers to the cat, yes, it's okay.
  • < – Ronald Sole – 2020-06-05T15:10:24.047


  • As I understand, "She isn't able to have drunk" is correct and possible but it's not used because of being "mouthful" which, as I can see" means "a lot of excessive words". 2) "It can be true" is itself bad or it's bad when it has "that he has forgotten"?
  • < – Michael Azarenko – 2020-06-05T15:33:00.973

    1@MichaelAzarenko No, "she isn't able= present, to have drunk=past: She wasn't able to have drunk. But we actually say: She couldn't have drunk. – Lambie – 2020-06-05T22:14:24.590

    Why is "She can't have drunk" okay if "can" - present too? – Michael Azarenko – 2020-06-06T01:51:19.470


    Your first substitution, "She isn't able to have drunk that much coffee." isn't possible because of the tense of "isn't". With "wasn't", it is possible but unlikely.

    For your second example, the original sentence, "It can be possible that..." is unlikely itself, because "can" and "be possible" are redundant:
    "It could be that he has forgotten" already means "It is possible that he has forgotten..."
    ("Could" is past tense form of "can".)

    That makes the substitution "It is able to be possible that...", basically impossible.

    Jack O'Flaherty

    Posted 2020-06-05T13:03:52.380

    Reputation: 16 815

    So, "She isn't able to have drunk that much coffee." is impossible but "She wasn't able to have drunk that much coffee." is possible but unlikely? What's changed? Only the tense, nothing else. How does it work?

    Okay, let's change it a little. "It can be true that he has forgotten..." = "It is able to be true that he has forgotten" – Michael Azarenko – 2020-06-05T14:29:24.243

    1First question, yes. Still unlikely, even with "wasn't". The rest of the sentence is speaking about the past, so you can't use the present tense "isn't". Second question, at Google books I find multiple instances of "it is able to be". The ones where "it" has a concrete antecedent seem like reasonable uses; the ones where it is a dummy pronoun, as in your example, seem very unidiomatic. – Jack O'Flaherty – 2020-06-05T14:47:50.287

    If I can't use "isn't" because the rest part is speaking about the past, how can I use "can't" if it's present, too? Concrete antecedent? – Michael Azarenko – 2020-06-05T14:57:20.373

    1No, you're mixing up two different answers. As to the tense, "couldn't have drunk" is probably the correct tense, but "can't have drunk" doesn't seem as impossible as "isn't able to have drunk". I'm not sure why. Maybe a new focused question would elicit a better answer. – Jack O'Flaherty – 2020-06-05T15:21:32.370

    2This isn't right. The utterance She isn't able to have drunk that much coffee might not be particularly *likely*, but it's syntactically fine, and quite capable of being meaningfully interpreted. – FumbleFingers Reinstate Monica – 2020-06-06T15:36:02.357

    1@FFRM, I disagree, not on syntactic but on semantic grounds. You'd be saying she is not able, at the present time, to have drunk that much in the past. – Jack O'Flaherty – 2020-06-06T15:41:43.017

    @FumbleFingersReinstateMonica, so it's a correct sentence? – Michael Azarenko – 2020-06-06T16:22:46.817

    2@Michael: For your purposes it's probably safer to just say it's *not* a "correct sentence". I'm simply arguing with Jack as regards whether it might be syntactically invalid and/or incapable of being parsed by a native speaker. But there's really no chance you would ever be likely to use such an utterance "correctly" even if both of us were to agree that it's at least "credible". – FumbleFingers Reinstate Monica – 2020-06-06T16:32:56.070

    But what's the problem? "can't have drunk" is okay but "isn't able to have drunk" is most likely not. "Can" and "be able to" can mean the same thing. They should be interchangeable here. All of this is very deplorable...:( – Michael Azarenko – 2020-06-06T16:38:20.337

    1@FFRM Just to clarify what I mean, I think "She can't have drunk that much." could be replaced by "It is not possible that she drank that much.", but not by "She is not able to have drunk that much."; so I think "can" can't always be replaced by "is able to", again on semantic grounds. – Jack O'Flaherty – 2020-06-06T16:43:52.243

    1@MichaelAzarenko Don't be sad! :-) – Jack O'Flaherty – 2020-06-06T16:44:44.857

    Hm, what about "could"? I heard it was totally okay to say "She wasn't able to have drunk" instead of "She couldn't have drunk". Seems to be "can't" can't here be replaced by "is not able" but "couldn't" can be replaced by "wasn't able". What a paradox... – Michael Azarenko – 2020-06-06T16:50:42.380

    @JackO'Flaherty "*She is not able to have drunk that much"* is grammatical. So is *she was not able to have drunk that much.* It's exactly the same as the optional backshifting in reported speech. Both of these are acceptable: (1) *She said the earth was round.* (2) *She said the earth is round.* The only difference is the emphasis. You might not *like* one of the forms, but that doesn't preclude its use by other people in a way that they understand.

    – Jason Bassford – 2020-06-06T19:21:33.830

    @JasonBassford On this one, at least for the example "She is not able...", I'll continue to disagree. – Jack O'Flaherty – 2020-06-06T19:55:30.117