I could oxygenate you could oxygenate she could oxygenate we could oxygenate you could oxygenate they could oxygenate
V-ing form
I could be oxygenating you could be oxygenating she could be oxygenating we could be oxygenating you could be oxygenating they could be oxygenating
Perfect
I could have oxygenated you could have oxygenated she could have oxygenated we could have oxygenated you could have oxygenated they could have oxygenated
V-ing perfect
I could have been oxygenating you could have been oxygenating she could have been oxygenating we could have been oxygenating you could have been oxygenating they could have been oxygenating
Negation
Simple form
I could not oxygenate you could not oxygenate she could not oxygenate we could not oxygenate you could not oxygenate they could not oxygenate
V-ing form
I could not be oxygenating you could not be oxygenating she could not be oxygenating we could not be oxygenating you could not be oxygenating they could not be oxygenating
Perfect
I could not have oxygenated you could not have oxygenated she could not have oxygenated we could not have oxygenated you could not have oxygenated they could not have oxygenated
V-ing perfect
I could not have been oxygenating you could not have been oxygenating she could not have been oxygenating we could not have been oxygenating you could not have been oxygenating they could not have been oxygenating
Interrogative form
Simple form
could I oxygenate? could you oxygenate? could she oxygenate? could we oxygenate? could you oxygenate? could they oxygenate?
V-ing form
could I be oxygenating? could you be oxygenating? could she be oxygenating? could we be oxygenating? could you be oxygenating? could they be oxygenating?
Perfect
could I have oxygenated? could you have oxygenated? could she have oxygenated? could we have oxygenated? could you have oxygenated? could they have oxygenated?
V-ing perfect
could I have been oxygenating? could you have been oxygenating? could she have been oxygenating? could we have been oxygenating? could you have been oxygenating? could they have been oxygenating?
Interro-negative form
Simple form
could I not oxygenate? could you not oxygenate? could she not oxygenate? could we not oxygenate? could you not oxygenate? could they not oxygenate?
V-ing form
could I not be oxygenating? could you not be oxygenating? could she not be oxygenating? could we not be oxygenating? could you not be oxygenating? could they not be oxygenating?
Perfect
could I not have oxygenated? could you not have oxygenated? could she not have oxygenated? could we not have oxygenated? could you not have oxygenated? could they not have oxygenated?
V-ing perfect
could I not have been oxygenating? could you not have been oxygenating? could she not have been oxygenating? could we not have been oxygenating? could you not have been oxygenating? could they not have been oxygenating?