could oxidize
Regular verb: oxidize - oxidized- oxidized

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could oxidize
you could oxidize
he could oxidize
we could oxidize
you could oxidize
they could oxidize 	I could be oxidizing
you could be oxidizing
he could be oxidizing
we could be oxidizing
you could be oxidizing
they could be oxidizing	I could have oxidized
you could have oxidized
he could have oxidized
we could have oxidized
you could have oxidized
they could have oxidized	I could have been oxidizing
you could have been oxidizing
he could have been oxidizing
we could have been oxidizing
you could have been oxidizing
they could have been oxidizing	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't oxidize
you couldn't oxidize
he couldn't oxidize
we couldn't oxidize
you couldn't oxidize
they couldn't oxidize 	I couldn't be oxidizing
you couldn't be oxidizing
he couldn't be oxidizing
we couldn't be oxidizing
you couldn't be oxidizing
they couldn't be oxidizing	I couldn't have oxidized
you couldn't have oxidized
he couldn't have oxidized
we couldn't have oxidized
you couldn't have oxidized
they couldn't have oxidized	I couldn't have been oxidizing
you couldn't have been oxidizing
he couldn't have been oxidizing
we couldn't have been oxidizing
you couldn't have been oxidizing
they couldn't have been oxidizing	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I oxidize?
could you oxidize?
could he oxidize?
could we oxidize?
could you oxidize?
could they oxidize? 	could I be oxidizing?
could you be oxidizing?
could he be oxidizing?
could we be oxidizing?
could you be oxidizing?
could they be oxidizing? 	could I have oxidized?
could you have oxidized?
could he have oxidized?
could we have oxidized?
could you have oxidized?
could they have oxidized? 	could I have been oxidizing?
could you have been oxidizing?
could he have been oxidizing?
could we have been oxidizing?
could you have been oxidizing?
could they have been oxidizing? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I oxidize?
couldn't you oxidize?
couldn't he oxidize?
couldn't we oxidize?
couldn't you oxidize?
couldn't they oxidize? 	couldn't I be oxidizing?
couldn't you be oxidizing?
couldn't he be oxidizing?
couldn't we be oxidizing?
couldn't you be oxidizing?
couldn't they be oxidizing? 	couldn't I have oxidized?
couldn't you have oxidized?
couldn't he have oxidized?
couldn't we have oxidized?
couldn't you have oxidized?
couldn't they have oxidized? 	couldn't I have been oxidizing?
couldn't you have been oxidizing?
couldn't he have been oxidizing?
couldn't we have been oxidizing?
couldn't you have been oxidizing?
couldn't they have been oxidizing?