I can juggle you can juggle he can juggle we can juggle you can juggle they can juggle
V-ing form
I can be juggling you can be juggling he can be juggling we can be juggling you can be juggling they can be juggling
Perfect
I can have juggled you can have juggled he can have juggled we can have juggled you can have juggled they can have juggled
V-ing perfect
I can have been juggling you can have been juggling he can have been juggling we can have been juggling you can have been juggling they can have been juggling
Negation
Simple form
I can't juggle you can't juggle he can't juggle we can't juggle you can't juggle they can't juggle
V-ing form
I can't be juggling you can't be juggling he can't be juggling we can't be juggling you can't be juggling they can't be juggling
Perfect
I can't have juggled you can't have juggled he can't have juggled we can't have juggled you can't have juggled they can't have juggled
V-ing perfect
I can't have been juggling you can't have been juggling he can't have been juggling we can't have been juggling you can't have been juggling they can't have been juggling
Interrogative form
Simple form
can I juggle? can you juggle? can he juggle? can we juggle? can you juggle? can they juggle?
V-ing form
can I be juggling? can you be juggling? can he be juggling? can we be juggling? can you be juggling? can they be juggling?
Perfect
can I have juggled? can you have juggled? can he have juggled? can we have juggled? can you have juggled? can they have juggled?
V-ing perfect
can I have been juggling? can you have been juggling? can he have been juggling? can we have been juggling? can you have been juggling? can they have been juggling?
Interro-negative form
Simple form
can't I juggle? can't you juggle? can't he juggle? can't we juggle? can't you juggle? can't they juggle?
V-ing form
can't I be juggling? can't you be juggling? can't he be juggling? can't we be juggling? can't you be juggling? can't they be juggling?
Perfect
can't I have juggled? can't you have juggled? can't he have juggled? can't we have juggled? can't you have juggled? can't they have juggled?
V-ing perfect
can't I have been juggling? can't you have been juggling? can't he have been juggling? can't we have been juggling? can't you have been juggling? can't they have been juggling?