English verb conjugation
COULD STAMP

Regular verb: stamp - stamped - stamped

Affirmation

Simple form	V-ing form
I could stamp you could stamp she could stamp we could stamp you could stamp they could stamp	I could be stamping you could be stamping she could be stamping we could be stamping you could be stamping they could be stamping
Perfect	V-ing perfect
I could have stamped you could have stamped she could have stamped we could have stamped you could have stamped they could have stamped	I could have been stamping you could have been stamping she could have been stamping we could have been stamping you could have been stamping they could have been stamping

Negation

Simple form	V-ing form
I couldn't stamp you couldn't stamp she couldn't stamp we couldn't stamp you couldn't stamp they couldn't stamp	I couldn't be stamping you couldn't be stamping she couldn't be stamping we couldn't be stamping you couldn't be stamping they couldn't be stamping
Perfect	V-ing perfect
I couldn't have stamped you couldn't have stamped she couldn't have stamped we couldn't have stamped you couldn't have stamped they couldn't have stamped	I couldn't have been stamping you couldn't have been stamping she couldn't have been stamping we couldn't have been stamping you couldn't have been stamping they couldn't have been stamping

Interrogative form

Simple form	V-ing form
could I stamp? could you stamp? could she stamp? could we stamp? could you stamp? could they stamp?	could I be stamping? could you be stamping? could she be stamping? could we be stamping? could you be stamping? could they be stamping?
Perfect	V-ing perfect
could I have stamped? could you have stamped? could she have stamped? could we have stamped? could you have stamped? could they have stamped?	could I have been stamping? could you have been stamping? could she have been stamping? could we have been stamping? could you have been stamping? could they have been stamping?

Interro-negative form

Simple form	V-ing form
couldn't I stamp? couldn't you stamp? couldn't she stamp? couldn't we stamp? couldn't you stamp? couldn't they stamp?	couldn't I be stamping? couldn't you be stamping? couldn't she be stamping? couldn't we be stamping? couldn't you be stamping? couldn't they be stamping?
Perfect	V-ing perfect
couldn't I have stamped? couldn't you have stamped? couldn't she have stamped? couldn't we have stamped? couldn't you have stamped? couldn't they have stamped?	couldn't I have been stamping? couldn't you have been stamping? couldn't she have been stamping? couldn't we have been stamping? couldn't you have been stamping? couldn't they have been stamping?