English verb conjugation
MUST YAK

Regular verb: yak - yaked - yaked

Affirmation

Simple form	V-ing form
I must yak you must yak he must yak we must yak you must yak they must yak	I must be yaking you must be yaking he must be yaking we must be yaking you must be yaking they must be yaking
Perfect	V-ing perfect
I must have yaked you must have yaked he must have yaked we must have yaked you must have yaked they must have yaked	I must have been yaking you must have been yaking he must have been yaking we must have been yaking you must have been yaking they must have been yaking

Negation

Simple form	V-ing form
I must not yak you must not yak he must not yak we must not yak you must not yak they must not yak	I must not be yaking you must not be yaking he must not be yaking we must not be yaking you must not be yaking they must not be yaking
Perfect	V-ing perfect
I must not have yaked you must not have yaked he must not have yaked we must not have yaked you must not have yaked they must not have yaked	I must not have been yaking you must not have been yaking he must not have been yaking we must not have been yaking you must not have been yaking they must not have been yaking

Interrogative form

Simple form	V-ing form
must I yak? must you yak? must he yak? must we yak? must you yak? must they yak?	must I be yaking? must you be yaking? must he be yaking? must we be yaking? must you be yaking? must they be yaking?
Perfect	V-ing perfect
must I have yaked? must you have yaked? must he have yaked? must we have yaked? must you have yaked? must they have yaked?	must I have been yaking? must you have been yaking? must he have been yaking? must we have been yaking? must you have been yaking? must they have been yaking?

Interro-negative form

Simple form	V-ing form
must I not yak? must you not yak? must he not yak? must we not yak? must you not yak? must they not yak?	must I not be yaking? must you not be yaking? must he not be yaking? must we not be yaking? must you not be yaking? must they not be yaking?
Perfect	V-ing perfect
must I not have yaked? must you not have yaked? must he not have yaked? must we not have yaked? must you not have yaked? must they not have yaked?	must I not have been yaking? must you not have been yaking? must he not have been yaking? must we not have been yaking? must you not have been yaking? must they not have been yaking?