I must classify you must classify he must classify we must classify you must classify they must classify
V-ing form
I must be classifying you must be classifying he must be classifying we must be classifying you must be classifying they must be classifying
Perfect
I must have classified you must have classified he must have classified we must have classified you must have classified they must have classified
V-ing perfect
I must have been classifying you must have been classifying he must have been classifying we must have been classifying you must have been classifying they must have been classifying
Negation
Simple form
I must not classify you must not classify he must not classify we must not classify you must not classify they must not classify
V-ing form
I must not be classifying you must not be classifying he must not be classifying we must not be classifying you must not be classifying they must not be classifying
Perfect
I must not have classified you must not have classified he must not have classified we must not have classified you must not have classified they must not have classified
V-ing perfect
I must not have been classifying you must not have been classifying he must not have been classifying we must not have been classifying you must not have been classifying they must not have been classifying
Interrogative form
Simple form
must I classify? must you classify? must he classify? must we classify? must you classify? must they classify?
V-ing form
must I be classifying? must you be classifying? must he be classifying? must we be classifying? must you be classifying? must they be classifying?
Perfect
must I have classified? must you have classified? must he have classified? must we have classified? must you have classified? must they have classified?
V-ing perfect
must I have been classifying? must you have been classifying? must he have been classifying? must we have been classifying? must you have been classifying? must they have been classifying?
Interro-negative form
Simple form
must I not classify? must you not classify? must he not classify? must we not classify? must you not classify? must they not classify?
V-ing form
must I not be classifying? must you not be classifying? must he not be classifying? must we not be classifying? must you not be classifying? must they not be classifying?
Perfect
must I not have classified? must you not have classified? must he not have classified? must we not have classified? must you not have classified? must they not have classified?
V-ing perfect
must I not have been classifying? must you not have been classifying? must he not have been classifying? must we not have been classifying? must you not have been classifying? must they not have been classifying?