English verb conjugation
COULD AFFIX

Regular verb: affix - affixed - affixed

Affirmation

Simple form	V-ing form
I could affix you could affix he could affix we could affix you could affix they could affix	I could be affixing you could be affixing he could be affixing we could be affixing you could be affixing they could be affixing
Perfect	V-ing perfect
I could have affixed you could have affixed he could have affixed we could have affixed you could have affixed they could have affixed	I could have been affixing you could have been affixing he could have been affixing we could have been affixing you could have been affixing they could have been affixing

Negation

Simple form	V-ing form
I could not affix you could not affix he could not affix we could not affix you could not affix they could not affix	I could not be affixing you could not be affixing he could not be affixing we could not be affixing you could not be affixing they could not be affixing
Perfect	V-ing perfect
I could not have affixed you could not have affixed he could not have affixed we could not have affixed you could not have affixed they could not have affixed	I could not have been affixing you could not have been affixing he could not have been affixing we could not have been affixing you could not have been affixing they could not have been affixing

Interrogative form

Simple form	V-ing form
could I affix? could you affix? could he affix? could we affix? could you affix? could they affix?	could I be affixing? could you be affixing? could he be affixing? could we be affixing? could you be affixing? could they be affixing?
Perfect	V-ing perfect
could I have affixed? could you have affixed? could he have affixed? could we have affixed? could you have affixed? could they have affixed?	could I have been affixing? could you have been affixing? could he have been affixing? could we have been affixing? could you have been affixing? could they have been affixing?

Interro-negative form

Simple form	V-ing form
could I not affix? could you not affix? could he not affix? could we not affix? could you not affix? could they not affix?	could I not be affixing? could you not be affixing? could he not be affixing? could we not be affixing? could you not be affixing? could they not be affixing?
Perfect	V-ing perfect
could I not have affixed? could you not have affixed? could he not have affixed? could we not have affixed? could you not have affixed? could they not have affixed?	could I not have been affixing? could you not have been affixing? could he not have been affixing? could we not have been affixing? could you not have been affixing? could they not have been affixing?