could percolate
Regular verb: percolate - percolated- percolated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could percolate
you could percolate
she could percolate
we could percolate
you could percolate
they could percolate 	I could be percolating
you could be percolating
she could be percolating
we could be percolating
you could be percolating
they could be percolating	I could have percolated
you could have percolated
she could have percolated
we could have percolated
you could have percolated
they could have percolated	I could have been percolating
you could have been percolating
she could have been percolating
we could have been percolating
you could have been percolating
they could have been percolating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not percolate
you could not percolate
she could not percolate
we could not percolate
you could not percolate
they could not percolate 	I could not be percolating
you could not be percolating
she could not be percolating
we could not be percolating
you could not be percolating
they could not be percolating	I could not have percolated
you could not have percolated
she could not have percolated
we could not have percolated
you could not have percolated
they could not have percolated	I could not have been percolating
you could not have been percolating
she could not have been percolating
we could not have been percolating
you could not have been percolating
they could not have been percolating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I percolate?
could you percolate?
could she percolate?
could we percolate?
could you percolate?
could they percolate? 	could I be percolating?
could you be percolating?
could she be percolating?
could we be percolating?
could you be percolating?
could they be percolating? 	could I have percolated?
could you have percolated?
could she have percolated?
could we have percolated?
could you have percolated?
could they have percolated? 	could I have been percolating?
could you have been percolating?
could she have been percolating?
could we have been percolating?
could you have been percolating?
could they have been percolating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not percolate?
could you not percolate?
could she not percolate?
could we not percolate?
could you not percolate?
could they not percolate? 	could I not be percolating?
could you not be percolating?
could she not be percolating?
could we not be percolating?
could you not be percolating?
could they not be percolating? 	could I not have percolated?
could you not have percolated?
could she not have percolated?
could we not have percolated?
could you not have percolated?
could they not have percolated? 	could I not have been percolating?
could you not have been percolating?
could she not have been percolating?
could we not have been percolating?
could you not have been percolating?
could they not have been percolating?