How did you know/how would you know

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How did you know it-- This is a simple inquiry about a past activity.

How would you know it-- This does not refer to a past activity. It is conditional: 'How would you know it [if you saw it, if it happened, etc]'. The past form of this conditional is 'How would you have known it [if you had seen it, etc.]'
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Hi Micawber,

Thanks for your reply ..but still I am not able to understand clearly.Could you please break it out in a smiple way.

I have seen in some english movies .they put "would" in questions for past activities ..like the below

Who would do this ( A rat was hit by a car)

How would you do this

Please explain me in which situations we can us

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have seen in some english movies .they put "would" in questions for past activities ..like the below

Who would do this ( A rat was hit by a car)-- This is not past; it is a question using the simple present and meaning 'Who would hypothetically do this sort of thing at any time?'

How would you do this?-- This too, though it lacks context, seems to mean '

Hi Micawber,

Thanks a lot .With your help I came to know one new thing i.e we can use "would" in present tense realted questions.

Please telll me ..Is there any a set of rules or in which cases we can "would" in present tense related questions.

I would appreciate all your help.

Thanks in advance
Daniel

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You can use it whenever you are forming a [url=]CONDITIONAL 2[/url] utterance.
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