I can suck you can suck she can suck we can suck you can suck they can suck
V-ing form
I can be sucking you can be sucking she can be sucking we can be sucking you can be sucking they can be sucking
Perfect
I can have sucked you can have sucked she can have sucked we can have sucked you can have sucked they can have sucked
V-ing perfect
I can have been sucking you can have been sucking she can have been sucking we can have been sucking you can have been sucking they can have been sucking
Negation
Simple form
I cannot suck you cannot suck she cannot suck we cannot suck you cannot suck they cannot suck
V-ing form
I cannot be sucking you cannot be sucking she cannot be sucking we cannot be sucking you cannot be sucking they cannot be sucking
Perfect
I cannot have sucked you cannot have sucked she cannot have sucked we cannot have sucked you cannot have sucked they cannot have sucked
V-ing perfect
I cannot have been sucking you cannot have been sucking she cannot have been sucking we cannot have been sucking you cannot have been sucking they cannot have been sucking
Interrogative form
Simple form
can I suck? can you suck? can she suck? can we suck? can you suck? can they suck?
V-ing form
can I be sucking? can you be sucking? can she be sucking? can we be sucking? can you be sucking? can they be sucking?
Perfect
can I have sucked? can you have sucked? can she have sucked? can we have sucked? can you have sucked? can they have sucked?
V-ing perfect
can I have been sucking? can you have been sucking? can she have been sucking? can we have been sucking? can you have been sucking? can they have been sucking?
Interro-negative form
Simple form
can I not suck? can you not suck? can she not suck? can we not suck? can you not suck? can they not suck?
V-ing form
can I not be sucking? can you not be sucking? can she not be sucking? can we not be sucking? can you not be sucking? can they not be sucking?
Perfect
can I not have sucked? can you not have sucked? can she not have sucked? can we not have sucked? can you not have sucked? can they not have sucked?
V-ing perfect
can I not have been sucking? can you not have been sucking? can she not have been sucking? can we not have been sucking? can you not have been sucking? can they not have been sucking?