I must elapse you must elapse she must elapse we must elapse you must elapse they must elapse
V-ing form
I must be elapsing you must be elapsing she must be elapsing we must be elapsing you must be elapsing they must be elapsing
Perfect
I must have elapsed you must have elapsed she must have elapsed we must have elapsed you must have elapsed they must have elapsed
V-ing perfect
I must have been elapsing you must have been elapsing she must have been elapsing we must have been elapsing you must have been elapsing they must have been elapsing
Negation
Simple form
I must not elapse you must not elapse she must not elapse we must not elapse you must not elapse they must not elapse
V-ing form
I must not be elapsing you must not be elapsing she must not be elapsing we must not be elapsing you must not be elapsing they must not be elapsing
Perfect
I must not have elapsed you must not have elapsed she must not have elapsed we must not have elapsed you must not have elapsed they must not have elapsed
V-ing perfect
I must not have been elapsing you must not have been elapsing she must not have been elapsing we must not have been elapsing you must not have been elapsing they must not have been elapsing
Interrogative form
Simple form
must I elapse? must you elapse? must she elapse? must we elapse? must you elapse? must they elapse?
V-ing form
must I be elapsing? must you be elapsing? must she be elapsing? must we be elapsing? must you be elapsing? must they be elapsing?
Perfect
must I have elapsed? must you have elapsed? must she have elapsed? must we have elapsed? must you have elapsed? must they have elapsed?
V-ing perfect
must I have been elapsing? must you have been elapsing? must she have been elapsing? must we have been elapsing? must you have been elapsing? must they have been elapsing?
Interro-negative form
Simple form
must I not elapse? must you not elapse? must she not elapse? must we not elapse? must you not elapse? must they not elapse?
V-ing form
must I not be elapsing? must you not be elapsing? must she not be elapsing? must we not be elapsing? must you not be elapsing? must they not be elapsing?
Perfect
must I not have elapsed? must you not have elapsed? must she not have elapsed? must we not have elapsed? must you not have elapsed? must they not have elapsed?
V-ing perfect
must I not have been elapsing? must you not have been elapsing? must she not have been elapsing? must we not have been elapsing? must you not have been elapsing? must they not have been elapsing?