I can finish you can finish he can finish we can finish you can finish they can finish
V-ing form
I can be finishing you can be finishing he can be finishing we can be finishing you can be finishing they can be finishing
Perfect
I can have finished you can have finished he can have finished we can have finished you can have finished they can have finished
V-ing perfect
I can have been finishing you can have been finishing he can have been finishing we can have been finishing you can have been finishing they can have been finishing
Negation
Simple form
I can't finish you can't finish he can't finish we can't finish you can't finish they can't finish
V-ing form
I can't be finishing you can't be finishing he can't be finishing we can't be finishing you can't be finishing they can't be finishing
Perfect
I can't have finished you can't have finished he can't have finished we can't have finished you can't have finished they can't have finished
V-ing perfect
I can't have been finishing you can't have been finishing he can't have been finishing we can't have been finishing you can't have been finishing they can't have been finishing
Interrogative form
Simple form
can I finish? can you finish? can he finish? can we finish? can you finish? can they finish?
V-ing form
can I be finishing? can you be finishing? can he be finishing? can we be finishing? can you be finishing? can they be finishing?
Perfect
can I have finished? can you have finished? can he have finished? can we have finished? can you have finished? can they have finished?
V-ing perfect
can I have been finishing? can you have been finishing? can he have been finishing? can we have been finishing? can you have been finishing? can they have been finishing?
Interro-negative form
Simple form
can't I finish? can't you finish? can't he finish? can't we finish? can't you finish? can't they finish?
V-ing form
can't I be finishing? can't you be finishing? can't he be finishing? can't we be finishing? can't you be finishing? can't they be finishing?
Perfect
can't I have finished? can't you have finished? can't he have finished? can't we have finished? can't you have finished? can't they have finished?
V-ing perfect
can't I have been finishing? can't you have been finishing? can't he have been finishing? can't we have been finishing? can't you have been finishing? can't they have been finishing?