English verb conjugation
COULD YAWP

Regular verb: yawp - yawped - yawped

Affirmation

Simple form	V-ing form
I could yawp you could yawp he could yawp we could yawp you could yawp they could yawp	I could be yawping you could be yawping he could be yawping we could be yawping you could be yawping they could be yawping
Perfect	V-ing perfect
I could have yawped you could have yawped he could have yawped we could have yawped you could have yawped they could have yawped	I could have been yawping you could have been yawping he could have been yawping we could have been yawping you could have been yawping they could have been yawping

Negation

Simple form	V-ing form
I could not yawp you could not yawp he could not yawp we could not yawp you could not yawp they could not yawp	I could not be yawping you could not be yawping he could not be yawping we could not be yawping you could not be yawping they could not be yawping
Perfect	V-ing perfect
I could not have yawped you could not have yawped he could not have yawped we could not have yawped you could not have yawped they could not have yawped	I could not have been yawping you could not have been yawping he could not have been yawping we could not have been yawping you could not have been yawping they could not have been yawping

Interrogative form

Simple form	V-ing form
could I yawp? could you yawp? could he yawp? could we yawp? could you yawp? could they yawp?	could I be yawping? could you be yawping? could he be yawping? could we be yawping? could you be yawping? could they be yawping?
Perfect	V-ing perfect
could I have yawped? could you have yawped? could he have yawped? could we have yawped? could you have yawped? could they have yawped?	could I have been yawping? could you have been yawping? could he have been yawping? could we have been yawping? could you have been yawping? could they have been yawping?

Interro-negative form

Simple form	V-ing form
could I not yawp? could you not yawp? could he not yawp? could we not yawp? could you not yawp? could they not yawp?	could I not be yawping? could you not be yawping? could he not be yawping? could we not be yawping? could you not be yawping? could they not be yawping?
Perfect	V-ing perfect
could I not have yawped? could you not have yawped? could he not have yawped? could we not have yawped? could you not have yawped? could they not have yawped?	could I not have been yawping? could you not have been yawping? could he not have been yawping? could we not have been yawping? could you not have been yawping? could they not have been yawping?