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