English verb conjugation
MUST PREINVESTIGATE

Regular verb: preinvestigate - preinvestigated - preinvestigated

Affirmation

Simple form	V-ing form
I must preinvestigate you must preinvestigate she must preinvestigate we must preinvestigate you must preinvestigate they must preinvestigate	I must be preinvestigating you must be preinvestigating she must be preinvestigating we must be preinvestigating you must be preinvestigating they must be preinvestigating
Perfect	V-ing perfect
I must have preinvestigated you must have preinvestigated she must have preinvestigated we must have preinvestigated you must have preinvestigated they must have preinvestigated	I must have been preinvestigating you must have been preinvestigating she must have been preinvestigating we must have been preinvestigating you must have been preinvestigating they must have been preinvestigating

Negation

Simple form	V-ing form
I must not preinvestigate you must not preinvestigate she must not preinvestigate we must not preinvestigate you must not preinvestigate they must not preinvestigate	I must not be preinvestigating you must not be preinvestigating she must not be preinvestigating we must not be preinvestigating you must not be preinvestigating they must not be preinvestigating
Perfect	V-ing perfect
I must not have preinvestigated you must not have preinvestigated she must not have preinvestigated we must not have preinvestigated you must not have preinvestigated they must not have preinvestigated	I must not have been preinvestigating you must not have been preinvestigating she must not have been preinvestigating we must not have been preinvestigating you must not have been preinvestigating they must not have been preinvestigating

Interrogative form

Simple form	V-ing form
must I preinvestigate? must you preinvestigate? must she preinvestigate? must we preinvestigate? must you preinvestigate? must they preinvestigate?	must I be preinvestigating? must you be preinvestigating? must she be preinvestigating? must we be preinvestigating? must you be preinvestigating? must they be preinvestigating?
Perfect	V-ing perfect
must I have preinvestigated? must you have preinvestigated? must she have preinvestigated? must we have preinvestigated? must you have preinvestigated? must they have preinvestigated?	must I have been preinvestigating? must you have been preinvestigating? must she have been preinvestigating? must we have been preinvestigating? must you have been preinvestigating? must they have been preinvestigating?

Interro-negative form

Simple form	V-ing form
must I not preinvestigate? must you not preinvestigate? must she not preinvestigate? must we not preinvestigate? must you not preinvestigate? must they not preinvestigate?	must I not be preinvestigating? must you not be preinvestigating? must she not be preinvestigating? must we not be preinvestigating? must you not be preinvestigating? must they not be preinvestigating?
Perfect	V-ing perfect
must I not have preinvestigated? must you not have preinvestigated? must she not have preinvestigated? must we not have preinvestigated? must you not have preinvestigated? must they not have preinvestigated?	must I not have been preinvestigating? must you not have been preinvestigating? must she not have been preinvestigating? must we not have been preinvestigating? must you not have been preinvestigating? must they not have been preinvestigating?