I can compute you can compute she can compute we can compute you can compute they can compute
V-ing form
I can be computing you can be computing she can be computing we can be computing you can be computing they can be computing
Perfect
I can have computed you can have computed she 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 she can have been computing we can have been computing you can have been computing they can have been computing
Negation
Simple form
I cannot compute you cannot compute she cannot compute we cannot compute you cannot compute they cannot compute
V-ing form
I cannot be computing you cannot be computing she cannot be computing we cannot be computing you cannot be computing they cannot be computing
Perfect
I cannot have computed you cannot have computed she cannot have computed we cannot have computed you cannot have computed they cannot have computed
V-ing perfect
I cannot have been computing you cannot have been computing she cannot have been computing we cannot have been computing you cannot have been computing they cannot have been computing
Interrogative form
Simple form
can I compute? can you compute? can she compute? can we compute? can you compute? can they compute?
V-ing form
can I be computing? can you be computing? can she be computing? can we be computing? can you be computing? can they be computing?
Perfect
can I have computed? can you have computed? can she 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 she have been computing? can we have been computing? can you have been computing? can they have been computing?
Interro-negative form
Simple form
can I not compute? can you not compute? can she not compute? can we not compute? can you not compute? can they not compute?
V-ing form
can I not be computing? can you not be computing? can she not be computing? can we not be computing? can you not be computing? can they not be computing?
Perfect
can I not have computed? can you not have computed? can she not have computed? can we not have computed? can you not have computed? can they not have computed?
V-ing perfect
can I not have been computing? can you not have been computing? can she not have been computing? can we not have been computing? can you not have been computing? can they not have been computing?