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 mustn't mast you mustn't mast he mustn't mast we mustn't mast you mustn't mast they mustn't mast	I mustn't be masting you mustn't be masting he mustn't be masting we mustn't be masting you mustn't be masting they mustn't be masting
Perfect	V-ing perfect
I mustn't have masted you mustn't have masted he mustn't have masted we mustn't have masted you mustn't have masted they mustn't have masted	I mustn't have been masting you mustn't have been masting he mustn't have been masting we mustn't have been masting you mustn't have been masting they mustn't 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
mustn't I mast? mustn't you mast? mustn't he mast? mustn't we mast? mustn't you mast? mustn't they mast?	mustn't I be masting? mustn't you be masting? mustn't he be masting? mustn't we be masting? mustn't you be masting? mustn't they be masting?
Perfect	V-ing perfect
mustn't I have masted? mustn't you have masted? mustn't he have masted? mustn't we have masted? mustn't you have masted? mustn't they have masted?	mustn't I have been masting? mustn't you have been masting? mustn't he have been masting? mustn't we have been masting? mustn't you have been masting? mustn't they have been masting?