English verb conjugation
CAN JOIN

Regular verb: join - joined - joined

Affirmation

Simple form	V-ing form
I can join you can join he can join we can join you can join they can join	I can be joining you can be joining he can be joining we can be joining you can be joining they can be joining
Perfect	V-ing perfect
I can have joined you can have joined he can have joined we can have joined you can have joined they can have joined	I can have been joining you can have been joining he can have been joining we can have been joining you can have been joining they can have been joining

Negation

Simple form	V-ing form
I cannot join you cannot join he cannot join we cannot join you cannot join they cannot join	I cannot be joining you cannot be joining he cannot be joining we cannot be joining you cannot be joining they cannot be joining
Perfect	V-ing perfect
I cannot have joined you cannot have joined he cannot have joined we cannot have joined you cannot have joined they cannot have joined	I cannot have been joining you cannot have been joining he cannot have been joining we cannot have been joining you cannot have been joining they cannot have been joining

Interrogative form

Simple form	V-ing form
can I join? can you join? can he join? can we join? can you join? can they join?	can I be joining? can you be joining? can he be joining? can we be joining? can you be joining? can they be joining?
Perfect	V-ing perfect
can I have joined? can you have joined? can he have joined? can we have joined? can you have joined? can they have joined?	can I have been joining? can you have been joining? can he have been joining? can we have been joining? can you have been joining? can they have been joining?

Interro-negative form

Simple form	V-ing form
can I not join? can you not join? can he not join? can we not join? can you not join? can they not join?	can I not be joining? can you not be joining? can he not be joining? can we not be joining? can you not be joining? can they not be joining?
Perfect	V-ing perfect
can I not have joined? can you not have joined? can he not have joined? can we not have joined? can you not have joined? can they not have joined?	can I not have been joining? can you not have been joining? can he not have been joining? can we not have been joining? can you not have been joining? can they not have been joining?