English verb conjugation
COULD PIPE

Regular verb: pipe - piped - piped

Affirmation

Simple form	V-ing form
I could pipe you could pipe she could pipe we could pipe you could pipe they could pipe	I could be piping you could be piping she could be piping we could be piping you could be piping they could be piping
Perfect	V-ing perfect
I could have piped you could have piped she could have piped we could have piped you could have piped they could have piped	I could have been piping you could have been piping she could have been piping we could have been piping you could have been piping they could have been piping

Negation

Simple form	V-ing form
I couldn't pipe you couldn't pipe she couldn't pipe we couldn't pipe you couldn't pipe they couldn't pipe	I couldn't be piping you couldn't be piping she couldn't be piping we couldn't be piping you couldn't be piping they couldn't be piping
Perfect	V-ing perfect
I couldn't have piped you couldn't have piped she couldn't have piped we couldn't have piped you couldn't have piped they couldn't have piped	I couldn't have been piping you couldn't have been piping she couldn't have been piping we couldn't have been piping you couldn't have been piping they couldn't have been piping

Interrogative form

Simple form	V-ing form
could I pipe? could you pipe? could she pipe? could we pipe? could you pipe? could they pipe?	could I be piping? could you be piping? could she be piping? could we be piping? could you be piping? could they be piping?
Perfect	V-ing perfect
could I have piped? could you have piped? could she have piped? could we have piped? could you have piped? could they have piped?	could I have been piping? could you have been piping? could she have been piping? could we have been piping? could you have been piping? could they have been piping?

Interro-negative form

Simple form	V-ing form
couldn't I pipe? couldn't you pipe? couldn't she pipe? couldn't we pipe? couldn't you pipe? couldn't they pipe?	couldn't I be piping? couldn't you be piping? couldn't she be piping? couldn't we be piping? couldn't you be piping? couldn't they be piping?
Perfect	V-ing perfect
couldn't I have piped? couldn't you have piped? couldn't she have piped? couldn't we have piped? couldn't you have piped? couldn't they have piped?	couldn't I have been piping? couldn't you have been piping? couldn't she have been piping? couldn't we have been piping? couldn't you have been piping? couldn't they have been piping?