I can compute you can compute he can compute we can compute you can compute they can compute
V-ing form
I can be computing you can be computing he can be computing we can be computing you can be computing they can be computing
Perfect
I can have computed you can have computed he can have computed we can have computed you can have computed they can have computed
V-ing perfect
I can have been computing you can have been computing he can have been computing we can have been computing you can have been computing they can have been computing
Negation
Simple form
I can't compute you can't compute he can't compute we can't compute you can't compute they can't compute
V-ing form
I can't be computing you can't be computing he can't be computing we can't be computing you can't be computing they can't be computing
Perfect
I can't have computed you can't have computed he can't have computed we can't have computed you can't have computed they can't have computed
V-ing perfect
I can't have been computing you can't have been computing he can't have been computing we can't have been computing you can't have been computing they can't have been computing
Interrogative form
Simple form
can I compute? can you compute? can he compute? can we compute? can you compute? can they compute?
V-ing form
can I be computing? can you be computing? can he be computing? can we be computing? can you be computing? can they be computing?
Perfect
can I have computed? can you have computed? can he have computed? can we have computed? can you have computed? can they have computed?
V-ing perfect
can I have been computing? can you have been computing? can he have been computing? can we have been computing? can you have been computing? can they have been computing?
Interro-negative form
Simple form
can't I compute? can't you compute? can't he compute? can't we compute? can't you compute? can't they compute?
V-ing form
can't I be computing? can't you be computing? can't he be computing? can't we be computing? can't you be computing? can't they be computing?
Perfect
can't I have computed? can't you have computed? can't he have computed? can't we have computed? can't you have computed? can't they have computed?
V-ing perfect
can't I have been computing? can't you have been computing? can't he have been computing? can't we have been computing? can't you have been computing? can't they have been computing?