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