I must welcome you must welcome he must welcome we must welcome you must welcome they must welcome
V-ing form
I must be welcoming you must be welcoming he must be welcoming we must be welcoming you must be welcoming they must be welcoming
Perfect
I must have welcomed you must have welcomed he must have welcomed we must have welcomed you must have welcomed they must have welcomed
V-ing perfect
I must have been welcoming you must have been welcoming he must have been welcoming we must have been welcoming you must have been welcoming they must have been welcoming
Negation
Simple form
I mustn't welcome you mustn't welcome he mustn't welcome we mustn't welcome you mustn't welcome they mustn't welcome
V-ing form
I mustn't be welcoming you mustn't be welcoming he mustn't be welcoming we mustn't be welcoming you mustn't be welcoming they mustn't be welcoming
Perfect
I mustn't have welcomed you mustn't have welcomed he mustn't have welcomed we mustn't have welcomed you mustn't have welcomed they mustn't have welcomed
V-ing perfect
I mustn't have been welcoming you mustn't have been welcoming he mustn't have been welcoming we mustn't have been welcoming you mustn't have been welcoming they mustn't have been welcoming
Interrogative form
Simple form
must I welcome? must you welcome? must he welcome? must we welcome? must you welcome? must they welcome?
V-ing form
must I be welcoming? must you be welcoming? must he be welcoming? must we be welcoming? must you be welcoming? must they be welcoming?
Perfect
must I have welcomed? must you have welcomed? must he have welcomed? must we have welcomed? must you have welcomed? must they have welcomed?
V-ing perfect
must I have been welcoming? must you have been welcoming? must he have been welcoming? must we have been welcoming? must you have been welcoming? must they have been welcoming?
Interro-negative form
Simple form
mustn't I welcome? mustn't you welcome? mustn't he welcome? mustn't we welcome? mustn't you welcome? mustn't they welcome?
V-ing form
mustn't I be welcoming? mustn't you be welcoming? mustn't he be welcoming? mustn't we be welcoming? mustn't you be welcoming? mustn't they be welcoming?
Perfect
mustn't I have welcomed? mustn't you have welcomed? mustn't he have welcomed? mustn't we have welcomed? mustn't you have welcomed? mustn't they have welcomed?
V-ing perfect
mustn't I have been welcoming? mustn't you have been welcoming? mustn't he have been welcoming? mustn't we have been welcoming? mustn't you have been welcoming? mustn't they have been welcoming?