could hydrogenize
Regular verb: hydrogenize - hydrogenized- hydrogenized

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could hydrogenize
you could hydrogenize
he could hydrogenize
we could hydrogenize
you could hydrogenize
they could hydrogenize 	I could be hydrogenizing
you could be hydrogenizing
he could be hydrogenizing
we could be hydrogenizing
you could be hydrogenizing
they could be hydrogenizing	I could have hydrogenized
you could have hydrogenized
he could have hydrogenized
we could have hydrogenized
you could have hydrogenized
they could have hydrogenized	I could have been hydrogenizing
you could have been hydrogenizing
he could have been hydrogenizing
we could have been hydrogenizing
you could have been hydrogenizing
they could have been hydrogenizing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't hydrogenize
you couldn't hydrogenize
he couldn't hydrogenize
we couldn't hydrogenize
you couldn't hydrogenize
they couldn't hydrogenize 	I couldn't be hydrogenizing
you couldn't be hydrogenizing
he couldn't be hydrogenizing
we couldn't be hydrogenizing
you couldn't be hydrogenizing
they couldn't be hydrogenizing	I couldn't have hydrogenized
you couldn't have hydrogenized
he couldn't have hydrogenized
we couldn't have hydrogenized
you couldn't have hydrogenized
they couldn't have hydrogenized	I couldn't have been hydrogenizing
you couldn't have been hydrogenizing
he couldn't have been hydrogenizing
we couldn't have been hydrogenizing
you couldn't have been hydrogenizing
they couldn't have been hydrogenizing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I hydrogenize?
could you hydrogenize?
could he hydrogenize?
could we hydrogenize?
could you hydrogenize?
could they hydrogenize? 	could I be hydrogenizing?
could you be hydrogenizing?
could he be hydrogenizing?
could we be hydrogenizing?
could you be hydrogenizing?
could they be hydrogenizing? 	could I have hydrogenized?
could you have hydrogenized?
could he have hydrogenized?
could we have hydrogenized?
could you have hydrogenized?
could they have hydrogenized? 	could I have been hydrogenizing?
could you have been hydrogenizing?
could he have been hydrogenizing?
could we have been hydrogenizing?
could you have been hydrogenizing?
could they have been hydrogenizing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I hydrogenize?
couldn't you hydrogenize?
couldn't he hydrogenize?
couldn't we hydrogenize?
couldn't you hydrogenize?
couldn't they hydrogenize? 	couldn't I be hydrogenizing?
couldn't you be hydrogenizing?
couldn't he be hydrogenizing?
couldn't we be hydrogenizing?
couldn't you be hydrogenizing?
couldn't they be hydrogenizing? 	couldn't I have hydrogenized?
couldn't you have hydrogenized?
couldn't he have hydrogenized?
couldn't we have hydrogenized?
couldn't you have hydrogenized?
couldn't they have hydrogenized? 	couldn't I have been hydrogenizing?
couldn't you have been hydrogenizing?
couldn't he have been hydrogenizing?
couldn't we have been hydrogenizing?
couldn't you have been hydrogenizing?
couldn't they have been hydrogenizing?