I must collect you must collect he must collect we must collect you must collect they must collect
V-ing form
I must be collecting you must be collecting he must be collecting we must be collecting you must be collecting they must be collecting
Perfect
I must have collected you must have collected he 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 he must have been collecting we must have been collecting you must have been collecting they must have been collecting
Negation
Simple form
I must not collect you must not collect he must not collect we must not collect you must not collect they must not collect
V-ing form
I must not be collecting you must not be collecting he must not be collecting we must not be collecting you must not be collecting they must not be collecting
Perfect
I must not have collected you must not have collected he must not have collected we must not have collected you must not have collected they must not have collected
V-ing perfect
I must not have been collecting you must not have been collecting he must not have been collecting we must not have been collecting you must not have been collecting they must not have been collecting
Interrogative form
Simple form
must I collect? must you collect? must he collect? must we collect? must you collect? must they collect?
V-ing form
must I be collecting? must you be collecting? must he be collecting? must we be collecting? must you be collecting? must they be collecting?
Perfect
must I have collected? must you have collected? must he 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 he have been collecting? must we have been collecting? must you have been collecting? must they have been collecting?
Interro-negative form
Simple form
must I not collect? must you not collect? must he not collect? must we not collect? must you not collect? must they not collect?
V-ing form
must I not be collecting? must you not be collecting? must he not be collecting? must we not be collecting? must you not be collecting? must they not be collecting?
Perfect
must I not have collected? must you not have collected? must he not have collected? must we not have collected? must you not have collected? must they not have collected?
V-ing perfect
must I not have been collecting? must you not have been collecting? must he not have been collecting? must we not have been collecting? must you not have been collecting? must they not have been collecting?