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 can't goof you can't goof she can't goof we can't goof you can't goof they can't goof
V-ing form
I can't be goofing you can't be goofing she can't be goofing we can't be goofing you can't be goofing they can't be goofing
Perfect
I can't have goofed you can't have goofed she can't have goofed we can't have goofed you can't have goofed they can't have goofed
V-ing perfect
I can't have been goofing you can't have been goofing she can't have been goofing we can't have been goofing you can't have been goofing they can't 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't I goof? can't you goof? can't she goof? can't we goof? can't you goof? can't they goof?
V-ing form
can't I be goofing? can't you be goofing? can't she be goofing? can't we be goofing? can't you be goofing? can't they be goofing?
Perfect
can't I have goofed? can't you have goofed? can't she have goofed? can't we have goofed? can't you have goofed? can't they have goofed?
V-ing perfect
can't I have been goofing? can't you have been goofing? can't she have been goofing? can't we have been goofing? can't you have been goofing? can't they have been goofing?