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