English verb conjugation
MUST ENQUIRE

Regular verb: enquire - enquired - enquired

Affirmation

Simple form	V-ing form
I must enquire you must enquire she must enquire we must enquire you must enquire they must enquire	I must be enquiring you must be enquiring she must be enquiring we must be enquiring you must be enquiring they must be enquiring
Perfect	V-ing perfect
I must have enquired you must have enquired she must have enquired we must have enquired you must have enquired they must have enquired	I must have been enquiring you must have been enquiring she must have been enquiring we must have been enquiring you must have been enquiring they must have been enquiring

Negation

Simple form	V-ing form
I must not enquire you must not enquire she must not enquire we must not enquire you must not enquire they must not enquire	I must not be enquiring you must not be enquiring she must not be enquiring we must not be enquiring you must not be enquiring they must not be enquiring
Perfect	V-ing perfect
I must not have enquired you must not have enquired she must not have enquired we must not have enquired you must not have enquired they must not have enquired	I must not have been enquiring you must not have been enquiring she must not have been enquiring we must not have been enquiring you must not have been enquiring they must not have been enquiring

Interrogative form

Simple form	V-ing form
must I enquire? must you enquire? must she enquire? must we enquire? must you enquire? must they enquire?	must I be enquiring? must you be enquiring? must she be enquiring? must we be enquiring? must you be enquiring? must they be enquiring?
Perfect	V-ing perfect
must I have enquired? must you have enquired? must she have enquired? must we have enquired? must you have enquired? must they have enquired?	must I have been enquiring? must you have been enquiring? must she have been enquiring? must we have been enquiring? must you have been enquiring? must they have been enquiring?

Interro-negative form

Simple form	V-ing form
must I not enquire? must you not enquire? must she not enquire? must we not enquire? must you not enquire? must they not enquire?	must I not be enquiring? must you not be enquiring? must she not be enquiring? must we not be enquiring? must you not be enquiring? must they not be enquiring?
Perfect	V-ing perfect
must I not have enquired? must you not have enquired? must she not have enquired? must we not have enquired? must you not have enquired? must they not have enquired?	must I not have been enquiring? must you not have been enquiring? must she not have been enquiring? must we not have been enquiring? must you not have been enquiring? must they not have been enquiring?