I could plague you could plague he could plague we could plague you could plague they could plague
V-ing form
I could be plaguing you could be plaguing he could be plaguing we could be plaguing you could be plaguing they could be plaguing
Perfect
I could have plagued you could have plagued he could have plagued we could have plagued you could have plagued they could have plagued
V-ing perfect
I could have been plaguing you could have been plaguing he could have been plaguing we could have been plaguing you could have been plaguing they could have been plaguing
Negation
Simple form
I could not plague you could not plague he could not plague we could not plague you could not plague they could not plague
V-ing form
I could not be plaguing you could not be plaguing he could not be plaguing we could not be plaguing you could not be plaguing they could not be plaguing
Perfect
I could not have plagued you could not have plagued he could not have plagued we could not have plagued you could not have plagued they could not have plagued
V-ing perfect
I could not have been plaguing you could not have been plaguing he could not have been plaguing we could not have been plaguing you could not have been plaguing they could not have been plaguing
Interrogative form
Simple form
could I plague? could you plague? could he plague? could we plague? could you plague? could they plague?
V-ing form
could I be plaguing? could you be plaguing? could he be plaguing? could we be plaguing? could you be plaguing? could they be plaguing?
Perfect
could I have plagued? could you have plagued? could he have plagued? could we have plagued? could you have plagued? could they have plagued?
V-ing perfect
could I have been plaguing? could you have been plaguing? could he have been plaguing? could we have been plaguing? could you have been plaguing? could they have been plaguing?
Interro-negative form
Simple form
could I not plague? could you not plague? could he not plague? could we not plague? could you not plague? could they not plague?
V-ing form
could I not be plaguing? could you not be plaguing? could he not be plaguing? could we not be plaguing? could you not be plaguing? could they not be plaguing?
Perfect
could I not have plagued? could you not have plagued? could he not have plagued? could we not have plagued? could you not have plagued? could they not have plagued?
V-ing perfect
could I not have been plaguing? could you not have been plaguing? could he not have been plaguing? could we not have been plaguing? could you not have been plaguing? could they not have been plaguing?