could oxygenate
Regular verb: oxygenate - oxygenated- oxygenated

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I could oxygenate
you could oxygenate
he could oxygenate
we could oxygenate
you could oxygenate
they could oxygenate 	I could be oxygenating
you could be oxygenating
he could be oxygenating
we could be oxygenating
you could be oxygenating
they could be oxygenating	I could have oxygenated
you could have oxygenated
he could have oxygenated
we could have oxygenated
you could have oxygenated
they could have oxygenated	I could have been oxygenating
you could have been oxygenating
he could have been oxygenating
we could have been oxygenating
you could have been oxygenating
they could have been oxygenating	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I couldn't oxygenate
you couldn't oxygenate
he couldn't oxygenate
we couldn't oxygenate
you couldn't oxygenate
they couldn't oxygenate 	I couldn't be oxygenating
you couldn't be oxygenating
he couldn't be oxygenating
we couldn't be oxygenating
you couldn't be oxygenating
they couldn't be oxygenating	I couldn't have oxygenated
you couldn't have oxygenated
he couldn't have oxygenated
we couldn't have oxygenated
you couldn't have oxygenated
they couldn't have oxygenated	I couldn't have been oxygenating
you couldn't have been oxygenating
he couldn't have been oxygenating
we couldn't have been oxygenating
you couldn't have been oxygenating
they couldn't have been oxygenating	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
could I oxygenate?
could you oxygenate?
could he oxygenate?
could we oxygenate?
could you oxygenate?
could they oxygenate? 	could I be oxygenating?
could you be oxygenating?
could he be oxygenating?
could we be oxygenating?
could you be oxygenating?
could they be oxygenating? 	could I have oxygenated?
could you have oxygenated?
could he have oxygenated?
could we have oxygenated?
could you have oxygenated?
could they have oxygenated? 	could I have been oxygenating?
could you have been oxygenating?
could he have been oxygenating?
could we have been oxygenating?
could you have been oxygenating?
could they have been oxygenating? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
couldn't I oxygenate?
couldn't you oxygenate?
couldn't he oxygenate?
couldn't we oxygenate?
couldn't you oxygenate?
couldn't they oxygenate? 	couldn't I be oxygenating?
couldn't you be oxygenating?
couldn't he be oxygenating?
couldn't we be oxygenating?
couldn't you be oxygenating?
couldn't they be oxygenating? 	couldn't I have oxygenated?
couldn't you have oxygenated?
couldn't he have oxygenated?
couldn't we have oxygenated?
couldn't you have oxygenated?
couldn't they have oxygenated? 	couldn't I have been oxygenating?
couldn't you have been oxygenating?
couldn't he have been oxygenating?
couldn't we have been oxygenating?
couldn't you have been oxygenating?
couldn't they have been oxygenating?