English verb conjugation
CAN PIPE

Regular verb: pipe - piped - piped

Affirmation

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

Negation

Simple form	V-ing form
I cannot pipe you cannot pipe he cannot pipe we cannot pipe you cannot pipe they cannot pipe	I cannot be piping you cannot be piping he cannot be piping we cannot be piping you cannot be piping they cannot be piping
Perfect	V-ing perfect
I cannot have piped you cannot have piped he cannot have piped we cannot have piped you cannot have piped they cannot have piped	I cannot have been piping you cannot have been piping he cannot have been piping we cannot have been piping you cannot have been piping they cannot have been piping

Interrogative form

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

Interro-negative form

Simple form	V-ing form
can I not pipe? can you not pipe? can he not pipe? can we not pipe? can you not pipe? can they not pipe?	can I not be piping? can you not be piping? can he not be piping? can we not be piping? can you not be piping? can they not be piping?
Perfect	V-ing perfect
can I not have piped? can you not have piped? can he not have piped? can we not have piped? can you not have piped? can they not have piped?	can I not have been piping? can you not have been piping? can he not have been piping? can we not have been piping? can you not have been piping? can they not have been piping?