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 can't join you can't join she can't join we can't join you can't join they can't join
V-ing form
I can't be joining you can't be joining she can't be joining we can't be joining you can't be joining they can't be joining
Perfect
I can't have joined you can't have joined she can't have joined we can't have joined you can't have joined they can't have joined
V-ing perfect
I can't have been joining you can't have been joining she can't have been joining we can't have been joining you can't have been joining they can't 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't I join? can't you join? can't she join? can't we join? can't you join? can't they join?
V-ing form
can't I be joining? can't you be joining? can't she be joining? can't we be joining? can't you be joining? can't they be joining?
Perfect
can't I have joined? can't you have joined? can't she have joined? can't we have joined? can't you have joined? can't they have joined?
V-ing perfect
can't I have been joining? can't you have been joining? can't she have been joining? can't we have been joining? can't you have been joining? can't they have been joining?