I must join you must join he must join we must join you must join they must join
Forma con V-ing
I must be joining you must be joining he must be joining we must be joining you must be joining they must be joining
Perfecto
I must have joined you must have joined he must have joined we must have joined you must have joined they must have joined
Perfecto con V-ing
I must have been joining you must have been joining he must have been joining we must have been joining you must have been joining they must have been joining
Negación
Forma simple
I must not join you must not join he must not join we must not join you must not join they must not join
Forma con V-ing
I must not be joining you must not be joining he must not be joining we must not be joining you must not be joining they must not be joining
Perfecto
I must not have joined you must not have joined he must not have joined we must not have joined you must not have joined they must not have joined
Perfecto con V-ing
I must not have been joining you must not have been joining he must not have been joining we must not have been joining you must not have been joining they must not have been joining
Forma interrogativa
Forma simple
must I join? must you join? must he join? must we join? must you join? must they join?
Forma con V-ing
must I be joining? must you be joining? must he be joining? must we be joining? must you be joining? must they be joining?
Perfecto
must I have joined? must you have joined? must he have joined? must we have joined? must you have joined? must they have joined?
Perfecto con V-ing
must I have been joining? must you have been joining? must he have been joining? must we have been joining? must you have been joining? must they have been joining?
Forma interro-negativa
Forma simple
must I not join? must you not join? must he not join? must we not join? must you not join? must they not join?
Forma con V-ing
must I not be joining? must you not be joining? must he not be joining? must we not be joining? must you not be joining? must they not be joining?
Perfecto
must I not have joined? must you not have joined? must he not have joined? must we not have joined? must you not have joined? must they not have joined?
Perfecto con V-ing
must I not have been joining? must you not have been joining? must he not have been joining? must we not have been joining? must you not have been joining? must they not have been joining?