could attenuate
Regular verb: attenuate - attenuated- attenuated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could attenuate
you could attenuate
he could attenuate
we could attenuate
you could attenuate
they could attenuate 	I could be attenuating
you could be attenuating
he could be attenuating
we could be attenuating
you could be attenuating
they could be attenuating	I could have attenuated
you could have attenuated
he could have attenuated
we could have attenuated
you could have attenuated
they could have attenuated	I could have been attenuating
you could have been attenuating
he could have been attenuating
we could have been attenuating
you could have been attenuating
they could have been attenuating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't attenuate
you couldn't attenuate
he couldn't attenuate
we couldn't attenuate
you couldn't attenuate
they couldn't attenuate 	I couldn't be attenuating
you couldn't be attenuating
he couldn't be attenuating
we couldn't be attenuating
you couldn't be attenuating
they couldn't be attenuating	I couldn't have attenuated
you couldn't have attenuated
he couldn't have attenuated
we couldn't have attenuated
you couldn't have attenuated
they couldn't have attenuated	I couldn't have been attenuating
you couldn't have been attenuating
he couldn't have been attenuating
we couldn't have been attenuating
you couldn't have been attenuating
they couldn't have been attenuating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I attenuate?
could you attenuate?
could he attenuate?
could we attenuate?
could you attenuate?
could they attenuate? 	could I be attenuating?
could you be attenuating?
could he be attenuating?
could we be attenuating?
could you be attenuating?
could they be attenuating? 	could I have attenuated?
could you have attenuated?
could he have attenuated?
could we have attenuated?
could you have attenuated?
could they have attenuated? 	could I have been attenuating?
could you have been attenuating?
could he have been attenuating?
could we have been attenuating?
could you have been attenuating?
could they have been attenuating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I attenuate?
couldn't you attenuate?
couldn't he attenuate?
couldn't we attenuate?
couldn't you attenuate?
couldn't they attenuate? 	couldn't I be attenuating?
couldn't you be attenuating?
couldn't he be attenuating?
couldn't we be attenuating?
couldn't you be attenuating?
couldn't they be attenuating? 	couldn't I have attenuated?
couldn't you have attenuated?
couldn't he have attenuated?
couldn't we have attenuated?
couldn't you have attenuated?
couldn't they have attenuated? 	couldn't I have been attenuating?
couldn't you have been attenuating?
couldn't he have been attenuating?
couldn't we have been attenuating?
couldn't you have been attenuating?
couldn't they have been attenuating?