I could goof you could goof he could goof we could goof you could goof they could goof
V-ing form
I could be goofing you could be goofing he could be goofing we could be goofing you could be goofing they could be goofing
Perfect
I could have goofed you could have goofed he could have goofed we could have goofed you could have goofed they could have goofed
V-ing perfect
I could have been goofing you could have been goofing he could have been goofing we could have been goofing you could have been goofing they could have been goofing
Negation
Simple form
I could not goof you could not goof he could not goof we could not goof you could not goof they could not goof
V-ing form
I could not be goofing you could not be goofing he could not be goofing we could not be goofing you could not be goofing they could not be goofing
Perfect
I could not have goofed you could not have goofed he could not have goofed we could not have goofed you could not have goofed they could not have goofed
V-ing perfect
I could not have been goofing you could not have been goofing he could not have been goofing we could not have been goofing you could not have been goofing they could not have been goofing
Interrogative form
Simple form
could I goof? could you goof? could he goof? could we goof? could you goof? could they goof?
V-ing form
could I be goofing? could you be goofing? could he be goofing? could we be goofing? could you be goofing? could they be goofing?
Perfect
could I have goofed? could you have goofed? could he have goofed? could we have goofed? could you have goofed? could they have goofed?
V-ing perfect
could I have been goofing? could you have been goofing? could he have been goofing? could we have been goofing? could you have been goofing? could they have been goofing?
Interro-negative form
Simple form
could I not goof? could you not goof? could he not goof? could we not goof? could you not goof? could they not goof?
V-ing form
could I not be goofing? could you not be goofing? could he not be goofing? could we not be goofing? could you not be goofing? could they not be goofing?
Perfect
could I not have goofed? could you not have goofed? could he not have goofed? could we not have goofed? could you not have goofed? could they not have goofed?
V-ing perfect
could I not have been goofing? could you not have been goofing? could he not have been goofing? could we not have been goofing? could you not have been goofing? could they not have been goofing?