English verb conjugation
MUST BASE

Regular verb: base - based - based

Affirmation

Simple form	V-ing form
I must base you must base he must base we must base you must base they must base	I must be basing you must be basing he must be basing we must be basing you must be basing they must be basing
Perfect	V-ing perfect
I must have based you must have based he must have based we must have based you must have based they must have based	I must have been basing you must have been basing he must have been basing we must have been basing you must have been basing they must have been basing

Negation

Simple form	V-ing form
I must not base you must not base he must not base we must not base you must not base they must not base	I must not be basing you must not be basing he must not be basing we must not be basing you must not be basing they must not be basing
Perfect	V-ing perfect
I must not have based you must not have based he must not have based we must not have based you must not have based they must not have based	I must not have been basing you must not have been basing he must not have been basing we must not have been basing you must not have been basing they must not have been basing

Interrogative form

Simple form	V-ing form
must I base? must you base? must he base? must we base? must you base? must they base?	must I be basing? must you be basing? must he be basing? must we be basing? must you be basing? must they be basing?
Perfect	V-ing perfect
must I have based? must you have based? must he have based? must we have based? must you have based? must they have based?	must I have been basing? must you have been basing? must he have been basing? must we have been basing? must you have been basing? must they have been basing?

Interro-negative form

Simple form	V-ing form
must I not base? must you not base? must he not base? must we not base? must you not base? must they not base?	must I not be basing? must you not be basing? must he not be basing? must we not be basing? must you not be basing? must they not be basing?
Perfect	V-ing perfect
must I not have based? must you not have based? must he not have based? must we not have based? must you not have based? must they not have based?	must I not have been basing? must you not have been basing? must he not have been basing? must we not have been basing? must you not have been basing? must they not have been basing?