could hydrogenise
Regular verb: hydrogenise - hydrogenised- hydrogenised

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could hydrogenise
you could hydrogenise
she could hydrogenise
we could hydrogenise
you could hydrogenise
they could hydrogenise 	I could be hydrogenising
you could be hydrogenising
she could be hydrogenising
we could be hydrogenising
you could be hydrogenising
they could be hydrogenising	I could have hydrogenised
you could have hydrogenised
she 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
she 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
she 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
she 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
she 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
she 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 she hydrogenise?
could we hydrogenise?
could you hydrogenise?
could they hydrogenise? 	could I be hydrogenising?
could you be hydrogenising?
could she be hydrogenising?
could we be hydrogenising?
could you be hydrogenising?
could they be hydrogenising? 	could I have hydrogenised?
could you have hydrogenised?
could she 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 she 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 she 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 she 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 she 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 she have been hydrogenising?
couldn't we have been hydrogenising?
couldn't you have been hydrogenising?
couldn't they have been hydrogenising?