male gender | Modal : no | may | might | can | could | shall | should | will | would | must | ought to
English verb conjugation COULD KNOCK
Regular verb: knock - knocked - knocked
Affirmation
Simple form
I could knockyou could knock
she could knock
we could knock
you could knock
they could knock
V-ing form
I could be knockingyou could be knocking
she could be knocking
we could be knocking
you could be knocking
they could be knocking
Perfect
I could have knockedyou could have knocked
she could have knocked
we could have knocked
you could have knocked
they could have knocked
V-ing perfect
I could have been knockingyou could have been knocking
she could have been knocking
we could have been knocking
you could have been knocking
they could have been knocking
Negation
Simple form
I couldn't knockyou couldn't knock
she couldn't knock
we couldn't knock
you couldn't knock
they couldn't knock
V-ing form
I couldn't be knockingyou couldn't be knocking
she couldn't be knocking
we couldn't be knocking
you couldn't be knocking
they couldn't be knocking
Perfect
I couldn't have knockedyou couldn't have knocked
she couldn't have knocked
we couldn't have knocked
you couldn't have knocked
they couldn't have knocked
V-ing perfect
I couldn't have been knockingyou couldn't have been knocking
she couldn't have been knocking
we couldn't have been knocking
you couldn't have been knocking
they couldn't have been knocking
Interrogative form
Simple form
could I knock?could you knock?
could she knock?
could we knock?
could you knock?
could they knock?
V-ing form
could I be knocking?could you be knocking?
could she be knocking?
could we be knocking?
could you be knocking?
could they be knocking?
Perfect
could I have knocked?could you have knocked?
could she have knocked?
could we have knocked?
could you have knocked?
could they have knocked?
V-ing perfect
could I have been knocking?could you have been knocking?
could she have been knocking?
could we have been knocking?
could you have been knocking?
could they have been knocking?
Interro-negative form
Simple form
couldn't I knock?couldn't you knock?
couldn't she knock?
couldn't we knock?
couldn't you knock?
couldn't they knock?
V-ing form
couldn't I be knocking?couldn't you be knocking?
couldn't she be knocking?
couldn't we be knocking?
couldn't you be knocking?
couldn't they be knocking?
Perfect
couldn't I have knocked?couldn't you have knocked?
couldn't she have knocked?
couldn't we have knocked?
couldn't you have knocked?
couldn't they have knocked?
V-ing perfect
couldn't I have been knocking?couldn't you have been knocking?
couldn't she have been knocking?
couldn't we have been knocking?
couldn't you have been knocking?
couldn't they have been knocking?