I can group you can group he can group we can group you can group they can group
V-ing form
I can be grouping you can be grouping he can be grouping we can be grouping you can be grouping they can be grouping
Perfect
I can have grouped you can have grouped he can have grouped we can have grouped you can have grouped they can have grouped
V-ing perfect
I can have been grouping you can have been grouping he can have been grouping we can have been grouping you can have been grouping they can have been grouping
Negation
Simple form
I can't group you can't group he can't group we can't group you can't group they can't group
V-ing form
I can't be grouping you can't be grouping he can't be grouping we can't be grouping you can't be grouping they can't be grouping
Perfect
I can't have grouped you can't have grouped he can't have grouped we can't have grouped you can't have grouped they can't have grouped
V-ing perfect
I can't have been grouping you can't have been grouping he can't have been grouping we can't have been grouping you can't have been grouping they can't have been grouping
Interrogative form
Simple form
can I group? can you group? can he group? can we group? can you group? can they group?
V-ing form
can I be grouping? can you be grouping? can he be grouping? can we be grouping? can you be grouping? can they be grouping?
Perfect
can I have grouped? can you have grouped? can he have grouped? can we have grouped? can you have grouped? can they have grouped?
V-ing perfect
can I have been grouping? can you have been grouping? can he have been grouping? can we have been grouping? can you have been grouping? can they have been grouping?
Interro-negative form
Simple form
can't I group? can't you group? can't he group? can't we group? can't you group? can't they group?
V-ing form
can't I be grouping? can't you be grouping? can't he be grouping? can't we be grouping? can't you be grouping? can't they be grouping?
Perfect
can't I have grouped? can't you have grouped? can't he have grouped? can't we have grouped? can't you have grouped? can't they have grouped?
V-ing perfect
can't I have been grouping? can't you have been grouping? can't he have been grouping? can't we have been grouping? can't you have been grouping? can't they have been grouping?