I must endeavor you must endeavor she must endeavor we must endeavor you must endeavor they must endeavor
V-ing form
I must be endeavoring you must be endeavoring she must be endeavoring we must be endeavoring you must be endeavoring they must be endeavoring
Perfect
I must have endeavored you must have endeavored she must have endeavored we must have endeavored you must have endeavored they must have endeavored
V-ing perfect
I must have been endeavoring you must have been endeavoring she must have been endeavoring we must have been endeavoring you must have been endeavoring they must have been endeavoring
Negation
Simple form
I must not endeavor you must not endeavor she must not endeavor we must not endeavor you must not endeavor they must not endeavor
V-ing form
I must not be endeavoring you must not be endeavoring she must not be endeavoring we must not be endeavoring you must not be endeavoring they must not be endeavoring
Perfect
I must not have endeavored you must not have endeavored she must not have endeavored we must not have endeavored you must not have endeavored they must not have endeavored
V-ing perfect
I must not have been endeavoring you must not have been endeavoring she must not have been endeavoring we must not have been endeavoring you must not have been endeavoring they must not have been endeavoring
Interrogative form
Simple form
must I endeavor? must you endeavor? must she endeavor? must we endeavor? must you endeavor? must they endeavor?
V-ing form
must I be endeavoring? must you be endeavoring? must she be endeavoring? must we be endeavoring? must you be endeavoring? must they be endeavoring?
Perfect
must I have endeavored? must you have endeavored? must she have endeavored? must we have endeavored? must you have endeavored? must they have endeavored?
V-ing perfect
must I have been endeavoring? must you have been endeavoring? must she have been endeavoring? must we have been endeavoring? must you have been endeavoring? must they have been endeavoring?
Interro-negative form
Simple form
must I not endeavor? must you not endeavor? must she not endeavor? must we not endeavor? must you not endeavor? must they not endeavor?
V-ing form
must I not be endeavoring? must you not be endeavoring? must she not be endeavoring? must we not be endeavoring? must you not be endeavoring? must they not be endeavoring?
Perfect
must I not have endeavored? must you not have endeavored? must she not have endeavored? must we not have endeavored? must you not have endeavored? must they not have endeavored?
V-ing perfect
must I not have been endeavoring? must you not have been endeavoring? must she not have been endeavoring? must we not have been endeavoring? must you not have been endeavoring? must they not have been endeavoring?