could hydrogenise
Regular verb: hydrogenise - hydrogenised- hydrogenised

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could hydrogenise
you could hydrogenise
he could hydrogenise
we could hydrogenise
you could hydrogenise
they could hydrogenise 	I could be hydrogenising
you could be hydrogenising
he could be hydrogenising
we could be hydrogenising
you could be hydrogenising
they could be hydrogenising	I could have hydrogenised
you could have hydrogenised
he could have hydrogenised
we could have hydrogenised
you could have hydrogenised
they could have hydrogenised	I could have been hydrogenising
you could have been hydrogenising
he could have been hydrogenising
we could have been hydrogenising
you could have been hydrogenising
they could have been hydrogenising	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't hydrogenise
you couldn't hydrogenise
he couldn't hydrogenise
we couldn't hydrogenise
you couldn't hydrogenise
they couldn't hydrogenise 	I couldn't be hydrogenising
you couldn't be hydrogenising
he couldn't be hydrogenising
we couldn't be hydrogenising
you couldn't be hydrogenising
they couldn't be hydrogenising	I couldn't have hydrogenised
you couldn't have hydrogenised
he couldn't have hydrogenised
we couldn't have hydrogenised
you couldn't have hydrogenised
they couldn't have hydrogenised	I couldn't have been hydrogenising
you couldn't have been hydrogenising
he couldn't have been hydrogenising
we couldn't have been hydrogenising
you couldn't have been hydrogenising
they couldn't have been hydrogenising	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I hydrogenise?
could you hydrogenise?
could he hydrogenise?
could we hydrogenise?
could you hydrogenise?
could they hydrogenise? 	could I be hydrogenising?
could you be hydrogenising?
could he be hydrogenising?
could we be hydrogenising?
could you be hydrogenising?
could they be hydrogenising? 	could I have hydrogenised?
could you have hydrogenised?
could he have hydrogenised?
could we have hydrogenised?
could you have hydrogenised?
could they have hydrogenised? 	could I have been hydrogenising?
could you have been hydrogenising?
could he have been hydrogenising?
could we have been hydrogenising?
could you have been hydrogenising?
could they have been hydrogenising? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I hydrogenise?
couldn't you hydrogenise?
couldn't he hydrogenise?
couldn't we hydrogenise?
couldn't you hydrogenise?
couldn't they hydrogenise? 	couldn't I be hydrogenising?
couldn't you be hydrogenising?
couldn't he be hydrogenising?
couldn't we be hydrogenising?
couldn't you be hydrogenising?
couldn't they be hydrogenising? 	couldn't I have hydrogenised?
couldn't you have hydrogenised?
couldn't he have hydrogenised?
couldn't we have hydrogenised?
couldn't you have hydrogenised?
couldn't they have hydrogenised? 	couldn't I have been hydrogenising?
couldn't you have been hydrogenising?
couldn't he have been hydrogenising?
couldn't we have been hydrogenising?
couldn't you have been hydrogenising?
couldn't they have been hydrogenising?