English verb conjugation
MUST YAW

Regular verb: yaw - yawed - yawed

Affirmation

Simple form	V-ing form
I must yaw you must yaw he must yaw we must yaw you must yaw they must yaw	I must be yawing you must be yawing he must be yawing we must be yawing you must be yawing they must be yawing
Perfect	V-ing perfect
I must have yawed you must have yawed he must have yawed we must have yawed you must have yawed they must have yawed	I must have been yawing you must have been yawing he must have been yawing we must have been yawing you must have been yawing they must have been yawing

Negation

Simple form	V-ing form
I mustn't yaw you mustn't yaw he mustn't yaw we mustn't yaw you mustn't yaw they mustn't yaw	I mustn't be yawing you mustn't be yawing he mustn't be yawing we mustn't be yawing you mustn't be yawing they mustn't be yawing
Perfect	V-ing perfect
I mustn't have yawed you mustn't have yawed he mustn't have yawed we mustn't have yawed you mustn't have yawed they mustn't have yawed	I mustn't have been yawing you mustn't have been yawing he mustn't have been yawing we mustn't have been yawing you mustn't have been yawing they mustn't have been yawing

Interrogative form

Simple form	V-ing form
must I yaw? must you yaw? must he yaw? must we yaw? must you yaw? must they yaw?	must I be yawing? must you be yawing? must he be yawing? must we be yawing? must you be yawing? must they be yawing?
Perfect	V-ing perfect
must I have yawed? must you have yawed? must he have yawed? must we have yawed? must you have yawed? must they have yawed?	must I have been yawing? must you have been yawing? must he have been yawing? must we have been yawing? must you have been yawing? must they have been yawing?

Interro-negative form

Simple form	V-ing form
mustn't I yaw? mustn't you yaw? mustn't he yaw? mustn't we yaw? mustn't you yaw? mustn't they yaw?	mustn't I be yawing? mustn't you be yawing? mustn't he be yawing? mustn't we be yawing? mustn't you be yawing? mustn't they be yawing?
Perfect	V-ing perfect
mustn't I have yawed? mustn't you have yawed? mustn't he have yawed? mustn't we have yawed? mustn't you have yawed? mustn't they have yawed?	mustn't I have been yawing? mustn't you have been yawing? mustn't he have been yawing? mustn't we have been yawing? mustn't you have been yawing? mustn't they have been yawing?