I could usurp you could usurp he could usurp we could usurp you could usurp they could usurp
V-ing form
I could be usurping you could be usurping he could be usurping we could be usurping you could be usurping they could be usurping
Perfect
I could have usurped you could have usurped he could have usurped we could have usurped you could have usurped they could have usurped
V-ing perfect
I could have been usurping you could have been usurping he could have been usurping we could have been usurping you could have been usurping they could have been usurping
Negation
Simple form
I couldn't usurp you couldn't usurp he couldn't usurp we couldn't usurp you couldn't usurp they couldn't usurp
V-ing form
I couldn't be usurping you couldn't be usurping he couldn't be usurping we couldn't be usurping you couldn't be usurping they couldn't be usurping
Perfect
I couldn't have usurped you couldn't have usurped he couldn't have usurped we couldn't have usurped you couldn't have usurped they couldn't have usurped
V-ing perfect
I couldn't have been usurping you couldn't have been usurping he couldn't have been usurping we couldn't have been usurping you couldn't have been usurping they couldn't have been usurping
Interrogative form
Simple form
could I usurp? could you usurp? could he usurp? could we usurp? could you usurp? could they usurp?
V-ing form
could I be usurping? could you be usurping? could he be usurping? could we be usurping? could you be usurping? could they be usurping?
Perfect
could I have usurped? could you have usurped? could he have usurped? could we have usurped? could you have usurped? could they have usurped?
V-ing perfect
could I have been usurping? could you have been usurping? could he have been usurping? could we have been usurping? could you have been usurping? could they have been usurping?
Interro-negative form
Simple form
couldn't I usurp? couldn't you usurp? couldn't he usurp? couldn't we usurp? couldn't you usurp? couldn't they usurp?
V-ing form
couldn't I be usurping? couldn't you be usurping? couldn't he be usurping? couldn't we be usurping? couldn't you be usurping? couldn't they be usurping?
Perfect
couldn't I have usurped? couldn't you have usurped? couldn't he have usurped? couldn't we have usurped? couldn't you have usurped? couldn't they have usurped?
V-ing perfect
couldn't I have been usurping? couldn't you have been usurping? couldn't he have been usurping? couldn't we have been usurping? couldn't you have been usurping? couldn't they have been usurping?