could suction
Regular verb: suction - suctioned- suctioned

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could suction
you could suction
she could suction
we could suction
you could suction
they could suction 	I could be suctioning
you could be suctioning
she could be suctioning
we could be suctioning
you could be suctioning
they could be suctioning	I could have suctioned
you could have suctioned
she could have suctioned
we could have suctioned
you could have suctioned
they could have suctioned	I could have been suctioning
you could have been suctioning
she could have been suctioning
we could have been suctioning
you could have been suctioning
they could have been suctioning	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't suction
you couldn't suction
she couldn't suction
we couldn't suction
you couldn't suction
they couldn't suction 	I couldn't be suctioning
you couldn't be suctioning
she couldn't be suctioning
we couldn't be suctioning
you couldn't be suctioning
they couldn't be suctioning	I couldn't have suctioned
you couldn't have suctioned
she couldn't have suctioned
we couldn't have suctioned
you couldn't have suctioned
they couldn't have suctioned	I couldn't have been suctioning
you couldn't have been suctioning
she couldn't have been suctioning
we couldn't have been suctioning
you couldn't have been suctioning
they couldn't have been suctioning	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I suction?
could you suction?
could she suction?
could we suction?
could you suction?
could they suction? 	could I be suctioning?
could you be suctioning?
could she be suctioning?
could we be suctioning?
could you be suctioning?
could they be suctioning? 	could I have suctioned?
could you have suctioned?
could she have suctioned?
could we have suctioned?
could you have suctioned?
could they have suctioned? 	could I have been suctioning?
could you have been suctioning?
could she have been suctioning?
could we have been suctioning?
could you have been suctioning?
could they have been suctioning? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I suction?
couldn't you suction?
couldn't she suction?
couldn't we suction?
couldn't you suction?
couldn't they suction? 	couldn't I be suctioning?
couldn't you be suctioning?
couldn't she be suctioning?
couldn't we be suctioning?
couldn't you be suctioning?
couldn't they be suctioning? 	couldn't I have suctioned?
couldn't you have suctioned?
couldn't she have suctioned?
couldn't we have suctioned?
couldn't you have suctioned?
couldn't they have suctioned? 	couldn't I have been suctioning?
couldn't you have been suctioning?
couldn't she have been suctioning?
couldn't we have been suctioning?
couldn't you have been suctioning?
couldn't they have been suctioning?