could filtrate
Regular verb: filtrate - filtrated- filtrated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could filtrate
you could filtrate
she could filtrate
we could filtrate
you could filtrate
they could filtrate 	I could be filtrating
you could be filtrating
she could be filtrating
we could be filtrating
you could be filtrating
they could be filtrating	I could have filtrated
you could have filtrated
she could have filtrated
we could have filtrated
you could have filtrated
they could have filtrated	I could have been filtrating
you could have been filtrating
she could have been filtrating
we could have been filtrating
you could have been filtrating
they could have been filtrating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't filtrate
you couldn't filtrate
she couldn't filtrate
we couldn't filtrate
you couldn't filtrate
they couldn't filtrate 	I couldn't be filtrating
you couldn't be filtrating
she couldn't be filtrating
we couldn't be filtrating
you couldn't be filtrating
they couldn't be filtrating	I couldn't have filtrated
you couldn't have filtrated
she couldn't have filtrated
we couldn't have filtrated
you couldn't have filtrated
they couldn't have filtrated	I couldn't have been filtrating
you couldn't have been filtrating
she couldn't have been filtrating
we couldn't have been filtrating
you couldn't have been filtrating
they couldn't have been filtrating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I filtrate?
could you filtrate?
could she filtrate?
could we filtrate?
could you filtrate?
could they filtrate? 	could I be filtrating?
could you be filtrating?
could she be filtrating?
could we be filtrating?
could you be filtrating?
could they be filtrating? 	could I have filtrated?
could you have filtrated?
could she have filtrated?
could we have filtrated?
could you have filtrated?
could they have filtrated? 	could I have been filtrating?
could you have been filtrating?
could she have been filtrating?
could we have been filtrating?
could you have been filtrating?
could they have been filtrating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I filtrate?
couldn't you filtrate?
couldn't she filtrate?
couldn't we filtrate?
couldn't you filtrate?
couldn't they filtrate? 	couldn't I be filtrating?
couldn't you be filtrating?
couldn't she be filtrating?
couldn't we be filtrating?
couldn't you be filtrating?
couldn't they be filtrating? 	couldn't I have filtrated?
couldn't you have filtrated?
couldn't she have filtrated?
couldn't we have filtrated?
couldn't you have filtrated?
couldn't they have filtrated? 	couldn't I have been filtrating?
couldn't you have been filtrating?
couldn't she have been filtrating?
couldn't we have been filtrating?
couldn't you have been filtrating?
couldn't they have been filtrating?