English verb conjugation
MUST YAP

Regular verb: yap - yapped - yapped

Affirmation

Simple form	V-ing form
I must yap you must yap he must yap we must yap you must yap they must yap	I must be yapping you must be yapping he must be yapping we must be yapping you must be yapping they must be yapping
Perfect	V-ing perfect
I must have yapped you must have yapped he must have yapped we must have yapped you must have yapped they must have yapped	I must have been yapping you must have been yapping he must have been yapping we must have been yapping you must have been yapping they must have been yapping

Negation

Simple form	V-ing form
I must not yap you must not yap he must not yap we must not yap you must not yap they must not yap	I must not be yapping you must not be yapping he must not be yapping we must not be yapping you must not be yapping they must not be yapping
Perfect	V-ing perfect
I must not have yapped you must not have yapped he must not have yapped we must not have yapped you must not have yapped they must not have yapped	I must not have been yapping you must not have been yapping he must not have been yapping we must not have been yapping you must not have been yapping they must not have been yapping

Interrogative form

Simple form	V-ing form
must I yap? must you yap? must he yap? must we yap? must you yap? must they yap?	must I be yapping? must you be yapping? must he be yapping? must we be yapping? must you be yapping? must they be yapping?
Perfect	V-ing perfect
must I have yapped? must you have yapped? must he have yapped? must we have yapped? must you have yapped? must they have yapped?	must I have been yapping? must you have been yapping? must he have been yapping? must we have been yapping? must you have been yapping? must they have been yapping?

Interro-negative form

Simple form	V-ing form
must I not yap? must you not yap? must he not yap? must we not yap? must you not yap? must they not yap?	must I not be yapping? must you not be yapping? must he not be yapping? must we not be yapping? must you not be yapping? must they not be yapping?
Perfect	V-ing perfect
must I not have yapped? must you not have yapped? must he not have yapped? must we not have yapped? must you not have yapped? must they not have yapped?	must I not have been yapping? must you not have been yapping? must he not have been yapping? must we not have been yapping? must you not have been yapping? must they not have been yapping?