How can or how could

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The new edition of the remarkable reference features 8, illustrations. Join Us. Learner's Dictionary on Twitter ». Look at these examples:. We often use could in a question to ask somebody to do something. The use of could in this way is fairly polite formal :. Although we look at be able to here, it is not a modal verb. It is simply the verb be plus an adjective able followed by the infinitive. We look at be able to here because we sometimes use it instead of can and could.

We use be able to to express ability. If we say "I am able to swim", it is like saying "I can swim". We sometimes use be able to instead of "can" or "could" for ability.

Be able to is possible in all tenses - but "can" is possible only in the present and "could" is possible only in the past for ability.

In addition, "can" and "could" have no infinitive form. So we use be able to when we want to use other tenses or the infinitive. EnglishClub : Learn English : Grammar : Verbs : Modals : can, could, be able to can, could, be able to can and could are modal auxiliary verbs.

The same main clause which is he could concentrate is used in a form of question. Instead of saying, i could concentrate with you, if you were not breathing on my neck, he used the interrogative form, how could i concentrate with you breathing on my neck?

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Create a free Team What is Teams? Learn more. Ask Question. Asked 4 years, 11 months ago. Active 4 years, 4 months ago. Viewed 18k times. Source I'm wondering whether I should use "can" or "could" in the following. I'd appreciate your help. Improve this question. Apollyon Apollyon 3, 4 4 gold badges 29 29 silver badges 60 60 bronze badges.

What's the context? For example, if it's said in relation to past behaviour or a past situation, use could. If for present or continuing, use can. Thank you for your first question! We need more context to give you a useful answer, though. As Lawrence says, either can or could might be appropriate here.

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