English verb conjugation
COULD PIN

Regular verb: pin - pinned - pinned

Affirmation

Simple form	V-ing form
I could pin you could pin he could pin we could pin you could pin they could pin	I could be pinning you could be pinning he could be pinning we could be pinning you could be pinning they could be pinning
Perfect	V-ing perfect
I could have pinned you could have pinned he could have pinned we could have pinned you could have pinned they could have pinned	I could have been pinning you could have been pinning he could have been pinning we could have been pinning you could have been pinning they could have been pinning

Negation

Simple form	V-ing form
I could not pin you could not pin he could not pin we could not pin you could not pin they could not pin	I could not be pinning you could not be pinning he could not be pinning we could not be pinning you could not be pinning they could not be pinning
Perfect	V-ing perfect
I could not have pinned you could not have pinned he could not have pinned we could not have pinned you could not have pinned they could not have pinned	I could not have been pinning you could not have been pinning he could not have been pinning we could not have been pinning you could not have been pinning they could not have been pinning

Interrogative form

Simple form	V-ing form
could I pin? could you pin? could he pin? could we pin? could you pin? could they pin?	could I be pinning? could you be pinning? could he be pinning? could we be pinning? could you be pinning? could they be pinning?
Perfect	V-ing perfect
could I have pinned? could you have pinned? could he have pinned? could we have pinned? could you have pinned? could they have pinned?	could I have been pinning? could you have been pinning? could he have been pinning? could we have been pinning? could you have been pinning? could they have been pinning?

Interro-negative form

Simple form	V-ing form
could I not pin? could you not pin? could he not pin? could we not pin? could you not pin? could they not pin?	could I not be pinning? could you not be pinning? could he not be pinning? could we not be pinning? could you not be pinning? could they not be pinning?
Perfect	V-ing perfect
could I not have pinned? could you not have pinned? could he not have pinned? could we not have pinned? could you not have pinned? could they not have pinned?	could I not have been pinning? could you not have been pinning? could he not have been pinning? could we not have been pinning? could you not have been pinning? could they not have been pinning?