I can brush you can brush she can brush we can brush you can brush they can brush
V-ing form
I can be brushing you can be brushing she can be brushing we can be brushing you can be brushing they can be brushing
Perfect
I can have brushed you can have brushed she can have brushed we can have brushed you can have brushed they can have brushed
V-ing perfect
I can have been brushing you can have been brushing she can have been brushing we can have been brushing you can have been brushing they can have been brushing
Negation
Simple form
I cannot brush you cannot brush she cannot brush we cannot brush you cannot brush they cannot brush
V-ing form
I cannot be brushing you cannot be brushing she cannot be brushing we cannot be brushing you cannot be brushing they cannot be brushing
Perfect
I cannot have brushed you cannot have brushed she cannot have brushed we cannot have brushed you cannot have brushed they cannot have brushed
V-ing perfect
I cannot have been brushing you cannot have been brushing she cannot have been brushing we cannot have been brushing you cannot have been brushing they cannot have been brushing
Interrogative form
Simple form
can I brush? can you brush? can she brush? can we brush? can you brush? can they brush?
V-ing form
can I be brushing? can you be brushing? can she be brushing? can we be brushing? can you be brushing? can they be brushing?
Perfect
can I have brushed? can you have brushed? can she have brushed? can we have brushed? can you have brushed? can they have brushed?
V-ing perfect
can I have been brushing? can you have been brushing? can she have been brushing? can we have been brushing? can you have been brushing? can they have been brushing?
Interro-negative form
Simple form
can I not brush? can you not brush? can she not brush? can we not brush? can you not brush? can they not brush?
V-ing form
can I not be brushing? can you not be brushing? can she not be brushing? can we not be brushing? can you not be brushing? can they not be brushing?
Perfect
can I not have brushed? can you not have brushed? can she not have brushed? can we not have brushed? can you not have brushed? can they not have brushed?
V-ing perfect
can I not have been brushing? can you not have been brushing? can she not have been brushing? can we not have been brushing? can you not have been brushing? can they not have been brushing?