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