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 couldn't affix you couldn't affix he couldn't affix we couldn't affix you couldn't affix they couldn't affix	I couldn't be affixing you couldn't be affixing he couldn't be affixing we couldn't be affixing you couldn't be affixing they couldn't be affixing
Perfect	V-ing perfect
I couldn't have affixed you couldn't have affixed he couldn't have affixed we couldn't have affixed you couldn't have affixed they couldn't have affixed	I couldn't have been affixing you couldn't have been affixing he couldn't have been affixing we couldn't have been affixing you couldn't have been affixing they couldn't 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
couldn't I affix? couldn't you affix? couldn't he affix? couldn't we affix? couldn't you affix? couldn't they affix?	couldn't I be affixing? couldn't you be affixing? couldn't he be affixing? couldn't we be affixing? couldn't you be affixing? couldn't they be affixing?
Perfect	V-ing perfect
couldn't I have affixed? couldn't you have affixed? couldn't he have affixed? couldn't we have affixed? couldn't you have affixed? couldn't they have affixed?	couldn't I have been affixing? couldn't you have been affixing? couldn't he have been affixing? couldn't we have been affixing? couldn't you have been affixing? couldn't they have been affixing?