English verb conjugation
MUST STRAIGHTEN

Regular verb: straighten - straightened - straightened

Affirmation

Simple form	V-ing form
I must straighten you must straighten he must straighten we must straighten you must straighten they must straighten	I must be straightening you must be straightening he must be straightening we must be straightening you must be straightening they must be straightening
Perfect	V-ing perfect
I must have straightened you must have straightened he must have straightened we must have straightened you must have straightened they must have straightened	I must have been straightening you must have been straightening he must have been straightening we must have been straightening you must have been straightening they must have been straightening

Negation

Simple form	V-ing form
I must not straighten you must not straighten he must not straighten we must not straighten you must not straighten they must not straighten	I must not be straightening you must not be straightening he must not be straightening we must not be straightening you must not be straightening they must not be straightening
Perfect	V-ing perfect
I must not have straightened you must not have straightened he must not have straightened we must not have straightened you must not have straightened they must not have straightened	I must not have been straightening you must not have been straightening he must not have been straightening we must not have been straightening you must not have been straightening they must not have been straightening

Interrogative form

Simple form	V-ing form
must I straighten? must you straighten? must he straighten? must we straighten? must you straighten? must they straighten?	must I be straightening? must you be straightening? must he be straightening? must we be straightening? must you be straightening? must they be straightening?
Perfect	V-ing perfect
must I have straightened? must you have straightened? must he have straightened? must we have straightened? must you have straightened? must they have straightened?	must I have been straightening? must you have been straightening? must he have been straightening? must we have been straightening? must you have been straightening? must they have been straightening?

Interro-negative form

Simple form	V-ing form
must I not straighten? must you not straighten? must he not straighten? must we not straighten? must you not straighten? must they not straighten?	must I not be straightening? must you not be straightening? must he not be straightening? must we not be straightening? must you not be straightening? must they not be straightening?
Perfect	V-ing perfect
must I not have straightened? must you not have straightened? must he not have straightened? must we not have straightened? must you not have straightened? must they not have straightened?	must I not have been straightening? must you not have been straightening? must he not have been straightening? must we not have been straightening? must you not have been straightening? must they not have been straightening?