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