I must collect you must collect she must collect we must collect you must collect they must collect
V-ing form
I must be collecting you must be collecting she must be collecting we must be collecting you must be collecting they must be collecting
Perfect
I must have collected you must have collected she must have collected we must have collected you must have collected they must have collected
V-ing perfect
I must have been collecting you must have been collecting she must have been collecting we must have been collecting you must have been collecting they must have been collecting
Negation
Simple form
I mustn't collect you mustn't collect she mustn't collect we mustn't collect you mustn't collect they mustn't collect
V-ing form
I mustn't be collecting you mustn't be collecting she mustn't be collecting we mustn't be collecting you mustn't be collecting they mustn't be collecting
Perfect
I mustn't have collected you mustn't have collected she mustn't have collected we mustn't have collected you mustn't have collected they mustn't have collected
V-ing perfect
I mustn't have been collecting you mustn't have been collecting she mustn't have been collecting we mustn't have been collecting you mustn't have been collecting they mustn't have been collecting
Interrogative form
Simple form
must I collect? must you collect? must she collect? must we collect? must you collect? must they collect?
V-ing form
must I be collecting? must you be collecting? must she be collecting? must we be collecting? must you be collecting? must they be collecting?
Perfect
must I have collected? must you have collected? must she have collected? must we have collected? must you have collected? must they have collected?
V-ing perfect
must I have been collecting? must you have been collecting? must she have been collecting? must we have been collecting? must you have been collecting? must they have been collecting?
Interro-negative form
Simple form
mustn't I collect? mustn't you collect? mustn't she collect? mustn't we collect? mustn't you collect? mustn't they collect?
V-ing form
mustn't I be collecting? mustn't you be collecting? mustn't she be collecting? mustn't we be collecting? mustn't you be collecting? mustn't they be collecting?
Perfect
mustn't I have collected? mustn't you have collected? mustn't she have collected? mustn't we have collected? mustn't you have collected? mustn't they have collected?
V-ing perfect
mustn't I have been collecting? mustn't you have been collecting? mustn't she have been collecting? mustn't we have been collecting? mustn't you have been collecting? mustn't they have been collecting?