could differentiate
Regular verb: differentiate - differentiated- differentiated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could differentiate
you could differentiate
he could differentiate
we could differentiate
you could differentiate
they could differentiate 	I could be differentiating
you could be differentiating
he could be differentiating
we could be differentiating
you could be differentiating
they could be differentiating	I could have differentiated
you could have differentiated
he could have differentiated
we could have differentiated
you could have differentiated
they could have differentiated	I could have been differentiating
you could have been differentiating
he could have been differentiating
we could have been differentiating
you could have been differentiating
they could have been differentiating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could not differentiate
you could not differentiate
he could not differentiate
we could not differentiate
you could not differentiate
they could not differentiate 	I could not be differentiating
you could not be differentiating
he could not be differentiating
we could not be differentiating
you could not be differentiating
they could not be differentiating	I could not have differentiated
you could not have differentiated
he could not have differentiated
we could not have differentiated
you could not have differentiated
they could not have differentiated	I could not have been differentiating
you could not have been differentiating
he could not have been differentiating
we could not have been differentiating
you could not have been differentiating
they could not have been differentiating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I differentiate?
could you differentiate?
could he differentiate?
could we differentiate?
could you differentiate?
could they differentiate? 	could I be differentiating?
could you be differentiating?
could he be differentiating?
could we be differentiating?
could you be differentiating?
could they be differentiating? 	could I have differentiated?
could you have differentiated?
could he have differentiated?
could we have differentiated?
could you have differentiated?
could they have differentiated? 	could I have been differentiating?
could you have been differentiating?
could he have been differentiating?
could we have been differentiating?
could you have been differentiating?
could they have been differentiating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I not differentiate?
could you not differentiate?
could he not differentiate?
could we not differentiate?
could you not differentiate?
could they not differentiate? 	could I not be differentiating?
could you not be differentiating?
could he not be differentiating?
could we not be differentiating?
could you not be differentiating?
could they not be differentiating? 	could I not have differentiated?
could you not have differentiated?
could he not have differentiated?
could we not have differentiated?
could you not have differentiated?
could they not have differentiated? 	could I not have been differentiating?
could you not have been differentiating?
could he not have been differentiating?
could we not have been differentiating?
could you not have been differentiating?
could they not have been differentiating?