I must sustain you must sustain she must sustain we must sustain you must sustain they must sustain
Forma con V-ing
I must be sustaining you must be sustaining she must be sustaining we must be sustaining you must be sustaining they must be sustaining
Perfecto
I must have sustained you must have sustained she must have sustained we must have sustained you must have sustained they must have sustained
Perfecto con V-ing
I must have been sustaining you must have been sustaining she must have been sustaining we must have been sustaining you must have been sustaining they must have been sustaining
Negación
Forma simple
I must not sustain you must not sustain she must not sustain we must not sustain you must not sustain they must not sustain
Forma con V-ing
I must not be sustaining you must not be sustaining she must not be sustaining we must not be sustaining you must not be sustaining they must not be sustaining
Perfecto
I must not have sustained you must not have sustained she must not have sustained we must not have sustained you must not have sustained they must not have sustained
Perfecto con V-ing
I must not have been sustaining you must not have been sustaining she must not have been sustaining we must not have been sustaining you must not have been sustaining they must not have been sustaining
Forma interrogativa
Forma simple
must I sustain? must you sustain? must she sustain? must we sustain? must you sustain? must they sustain?
Forma con V-ing
must I be sustaining? must you be sustaining? must she be sustaining? must we be sustaining? must you be sustaining? must they be sustaining?
Perfecto
must I have sustained? must you have sustained? must she have sustained? must we have sustained? must you have sustained? must they have sustained?
Perfecto con V-ing
must I have been sustaining? must you have been sustaining? must she have been sustaining? must we have been sustaining? must you have been sustaining? must they have been sustaining?
Forma interro-negativa
Forma simple
must I not sustain? must you not sustain? must she not sustain? must we not sustain? must you not sustain? must they not sustain?
Forma con V-ing
must I not be sustaining? must you not be sustaining? must she not be sustaining? must we not be sustaining? must you not be sustaining? must they not be sustaining?
Perfecto
must I not have sustained? must you not have sustained? must she not have sustained? must we not have sustained? must you not have sustained? must they not have sustained?
Perfecto con V-ing
must I not have been sustaining? must you not have been sustaining? must she not have been sustaining? must we not have been sustaining? must you not have been sustaining? must they not have been sustaining?