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