can suck
Regular verb: suck - sucked- sucked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I can suck
you can suck
she can suck
we can suck
you can suck
they can suck 	I can be sucking
you can be sucking
she can be sucking
we can be sucking
you can be sucking
they can be sucking	I can have sucked
you can have sucked
she can have sucked
we can have sucked
you can have sucked
they can have sucked	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 	V-ing form 	Perfect 	V-ing perfect 	
I cannot suck
you cannot suck
she cannot suck
we cannot suck
you cannot suck
they cannot suck 	I cannot be sucking
you cannot be sucking
she cannot be sucking
we cannot be sucking
you cannot be sucking
they cannot be sucking	I cannot have sucked
you cannot have sucked
she cannot have sucked
we cannot have sucked
you cannot have sucked
they cannot have sucked	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 	V-ing form 	Perfect 	V-ing perfect 	
can I suck?
can you suck?
can she suck?
can we suck?
can you suck?
can they suck? 	can I be sucking?
can you be sucking?
can she be sucking?
can we be sucking?
can you be sucking?
can they be sucking? 	can I have sucked?
can you have sucked?
can she have sucked?
can we have sucked?
can you have sucked?
can they have sucked? 	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 	V-ing form 	Perfect 	V-ing perfect 	
can I not suck?
can you not suck?
can she not suck?
can we not suck?
can you not suck?
can they not suck? 	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? 	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? 	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?