English verb conjugation
COULD EXCUSE

Regular verb: excuse - excused - excused

Affirmation

Simple form	V-ing form
I could excuse you could excuse he could excuse we could excuse you could excuse they could excuse	I could be excusing you could be excusing he could be excusing we could be excusing you could be excusing they could be excusing
Perfect	V-ing perfect
I could have excused you could have excused he could have excused we could have excused you could have excused they could have excused	I could have been excusing you could have been excusing he could have been excusing we could have been excusing you could have been excusing they could have been excusing

Negation

Simple form	V-ing form
I couldn't excuse you couldn't excuse he couldn't excuse we couldn't excuse you couldn't excuse they couldn't excuse	I couldn't be excusing you couldn't be excusing he couldn't be excusing we couldn't be excusing you couldn't be excusing they couldn't be excusing
Perfect	V-ing perfect
I couldn't have excused you couldn't have excused he couldn't have excused we couldn't have excused you couldn't have excused they couldn't have excused	I couldn't have been excusing you couldn't have been excusing he couldn't have been excusing we couldn't have been excusing you couldn't have been excusing they couldn't have been excusing

Interrogative form

Simple form	V-ing form
could I excuse? could you excuse? could he excuse? could we excuse? could you excuse? could they excuse?	could I be excusing? could you be excusing? could he be excusing? could we be excusing? could you be excusing? could they be excusing?
Perfect	V-ing perfect
could I have excused? could you have excused? could he have excused? could we have excused? could you have excused? could they have excused?	could I have been excusing? could you have been excusing? could he have been excusing? could we have been excusing? could you have been excusing? could they have been excusing?

Interro-negative form

Simple form	V-ing form
couldn't I excuse? couldn't you excuse? couldn't he excuse? couldn't we excuse? couldn't you excuse? couldn't they excuse?	couldn't I be excusing? couldn't you be excusing? couldn't he be excusing? couldn't we be excusing? couldn't you be excusing? couldn't they be excusing?
Perfect	V-ing perfect
couldn't I have excused? couldn't you have excused? couldn't he have excused? couldn't we have excused? couldn't you have excused? couldn't they have excused?	couldn't I have been excusing? couldn't you have been excusing? couldn't he have been excusing? couldn't we have been excusing? couldn't you have been excusing? couldn't they have been excusing?