I can join you can join she can join we can join you can join they can join
V-ing form
I can be joining you can be joining she can be joining we can be joining you can be joining they can be joining
Perfect
I can have joined you can have joined she can have joined we can have joined you can have joined they can have joined
V-ing perfect
I can have been joining you can have been joining she can have been joining we can have been joining you can have been joining they can have been joining
Negation
Simple form
I cannot join you cannot join she cannot join we cannot join you cannot join they cannot join
V-ing form
I cannot be joining you cannot be joining she cannot be joining we cannot be joining you cannot be joining they cannot be joining
Perfect
I cannot have joined you cannot have joined she cannot have joined we cannot have joined you cannot have joined they cannot have joined
V-ing perfect
I cannot have been joining you cannot have been joining she cannot have been joining we cannot have been joining you cannot have been joining they cannot have been joining
Interrogative form
Simple form
can I join? can you join? can she join? can we join? can you join? can they join?
V-ing form
can I be joining? can you be joining? can she be joining? can we be joining? can you be joining? can they be joining?
Perfect
can I have joined? can you have joined? can she have joined? can we have joined? can you have joined? can they have joined?
V-ing perfect
can I have been joining? can you have been joining? can she have been joining? can we have been joining? can you have been joining? can they have been joining?
Interro-negative form
Simple form
can I not join? can you not join? can she not join? can we not join? can you not join? can they not join?
V-ing form
can I not be joining? can you not be joining? can she not be joining? can we not be joining? can you not be joining? can they not be joining?
Perfect
can I not have joined? can you not have joined? can she not have joined? can we not have joined? can you not have joined? can they not have joined?
V-ing perfect
can I not have been joining? can you not have been joining? can she not have been joining? can we not have been joining? can you not have been joining? can they not have been joining?