English verb conjugation
MUST MAST

Regular verb: mast - masted - masted

Affirmation

Simple form	V-ing form
I must mast you must mast he must mast we must mast you must mast they must mast	I must be masting you must be masting he must be masting we must be masting you must be masting they must be masting
Perfect	V-ing perfect
I must have masted you must have masted he must have masted we must have masted you must have masted they must have masted	I must have been masting you must have been masting he must have been masting we must have been masting you must have been masting they must have been masting

Negation

Simple form	V-ing form
I must not mast you must not mast he must not mast we must not mast you must not mast they must not mast	I must not be masting you must not be masting he must not be masting we must not be masting you must not be masting they must not be masting
Perfect	V-ing perfect
I must not have masted you must not have masted he must not have masted we must not have masted you must not have masted they must not have masted	I must not have been masting you must not have been masting he must not have been masting we must not have been masting you must not have been masting they must not have been masting

Interrogative form

Simple form	V-ing form
must I mast? must you mast? must he mast? must we mast? must you mast? must they mast?	must I be masting? must you be masting? must he be masting? must we be masting? must you be masting? must they be masting?
Perfect	V-ing perfect
must I have masted? must you have masted? must he have masted? must we have masted? must you have masted? must they have masted?	must I have been masting? must you have been masting? must he have been masting? must we have been masting? must you have been masting? must they have been masting?

Interro-negative form

Simple form	V-ing form
must I not mast? must you not mast? must he not mast? must we not mast? must you not mast? must they not mast?	must I not be masting? must you not be masting? must he not be masting? must we not be masting? must you not be masting? must they not be masting?
Perfect	V-ing perfect
must I not have masted? must you not have masted? must he not have masted? must we not have masted? must you not have masted? must they not have masted?	must I not have been masting? must you not have been masting? must he not have been masting? must we not have been masting? must you not have been masting? must they not have been masting?