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 mustn't preinvestigate you mustn't preinvestigate she mustn't preinvestigate we mustn't preinvestigate you mustn't preinvestigate they mustn't preinvestigate	I mustn't be preinvestigating you mustn't be preinvestigating she mustn't be preinvestigating we mustn't be preinvestigating you mustn't be preinvestigating they mustn't be preinvestigating
Perfect	V-ing perfect
I mustn't have preinvestigated you mustn't have preinvestigated she mustn't have preinvestigated we mustn't have preinvestigated you mustn't have preinvestigated they mustn't have preinvestigated	I mustn't have been preinvestigating you mustn't have been preinvestigating she mustn't have been preinvestigating we mustn't have been preinvestigating you mustn't have been preinvestigating they mustn't 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
mustn't I preinvestigate? mustn't you preinvestigate? mustn't she preinvestigate? mustn't we preinvestigate? mustn't you preinvestigate? mustn't they preinvestigate?	mustn't I be preinvestigating? mustn't you be preinvestigating? mustn't she be preinvestigating? mustn't we be preinvestigating? mustn't you be preinvestigating? mustn't they be preinvestigating?
Perfect	V-ing perfect
mustn't I have preinvestigated? mustn't you have preinvestigated? mustn't she have preinvestigated? mustn't we have preinvestigated? mustn't you have preinvestigated? mustn't they have preinvestigated?	mustn't I have been preinvestigating? mustn't you have been preinvestigating? mustn't she have been preinvestigating? mustn't we have been preinvestigating? mustn't you have been preinvestigating? mustn't they have been preinvestigating?