English verb conjugation
MUST UNDERESTIMATE

Regular verb: underestimate - underestimated - underestimated

Affirmation

Simple form	V-ing form
I must underestimate you must underestimate he must underestimate we must underestimate you must underestimate they must underestimate	I must be underestimating you must be underestimating he must be underestimating we must be underestimating you must be underestimating they must be underestimating
Perfect	V-ing perfect
I must have underestimated you must have underestimated he must have underestimated we must have underestimated you must have underestimated they must have underestimated	I must have been underestimating you must have been underestimating he must have been underestimating we must have been underestimating you must have been underestimating they must have been underestimating

Negation

Simple form	V-ing form
I must not underestimate you must not underestimate he must not underestimate we must not underestimate you must not underestimate they must not underestimate	I must not be underestimating you must not be underestimating he must not be underestimating we must not be underestimating you must not be underestimating they must not be underestimating
Perfect	V-ing perfect
I must not have underestimated you must not have underestimated he must not have underestimated we must not have underestimated you must not have underestimated they must not have underestimated	I must not have been underestimating you must not have been underestimating he must not have been underestimating we must not have been underestimating you must not have been underestimating they must not have been underestimating

Interrogative form

Simple form	V-ing form
must I underestimate? must you underestimate? must he underestimate? must we underestimate? must you underestimate? must they underestimate?	must I be underestimating? must you be underestimating? must he be underestimating? must we be underestimating? must you be underestimating? must they be underestimating?
Perfect	V-ing perfect
must I have underestimated? must you have underestimated? must he have underestimated? must we have underestimated? must you have underestimated? must they have underestimated?	must I have been underestimating? must you have been underestimating? must he have been underestimating? must we have been underestimating? must you have been underestimating? must they have been underestimating?

Interro-negative form

Simple form	V-ing form
must I not underestimate? must you not underestimate? must he not underestimate? must we not underestimate? must you not underestimate? must they not underestimate?	must I not be underestimating? must you not be underestimating? must he not be underestimating? must we not be underestimating? must you not be underestimating? must they not be underestimating?
Perfect	V-ing perfect
must I not have underestimated? must you not have underestimated? must he not have underestimated? must we not have underestimated? must you not have underestimated? must they not have underestimated?	must I not have been underestimating? must you not have been underestimating? must he not have been underestimating? must we not have been underestimating? must you not have been underestimating? must they not have been underestimating?