English verb conjugation
COULD REPLACE

Regular verb: replace - replaced - replaced

Affirmation

Simple form	V-ing form
I could replace you could replace she could replace we could replace you could replace they could replace	I could be replacing you could be replacing she could be replacing we could be replacing you could be replacing they could be replacing
Perfect	V-ing perfect
I could have replaced you could have replaced she could have replaced we could have replaced you could have replaced they could have replaced	I could have been replacing you could have been replacing she could have been replacing we could have been replacing you could have been replacing they could have been replacing

Negation

Simple form	V-ing form
I couldn't replace you couldn't replace she couldn't replace we couldn't replace you couldn't replace they couldn't replace	I couldn't be replacing you couldn't be replacing she couldn't be replacing we couldn't be replacing you couldn't be replacing they couldn't be replacing
Perfect	V-ing perfect
I couldn't have replaced you couldn't have replaced she couldn't have replaced we couldn't have replaced you couldn't have replaced they couldn't have replaced	I couldn't have been replacing you couldn't have been replacing she couldn't have been replacing we couldn't have been replacing you couldn't have been replacing they couldn't have been replacing

Interrogative form

Simple form	V-ing form
could I replace? could you replace? could she replace? could we replace? could you replace? could they replace?	could I be replacing? could you be replacing? could she be replacing? could we be replacing? could you be replacing? could they be replacing?
Perfect	V-ing perfect
could I have replaced? could you have replaced? could she have replaced? could we have replaced? could you have replaced? could they have replaced?	could I have been replacing? could you have been replacing? could she have been replacing? could we have been replacing? could you have been replacing? could they have been replacing?

Interro-negative form

Simple form	V-ing form
couldn't I replace? couldn't you replace? couldn't she replace? couldn't we replace? couldn't you replace? couldn't they replace?	couldn't I be replacing? couldn't you be replacing? couldn't she be replacing? couldn't we be replacing? couldn't you be replacing? couldn't they be replacing?
Perfect	V-ing perfect
couldn't I have replaced? couldn't you have replaced? couldn't she have replaced? couldn't we have replaced? couldn't you have replaced? couldn't they have replaced?	couldn't I have been replacing? couldn't you have been replacing? couldn't she have been replacing? couldn't we have been replacing? couldn't you have been replacing? couldn't they have been replacing?