must be
Is certainly true
Must be expresses confident inference or logical conclusion about something's state: That must be the place, She must be exhausted after that flight.
The phrase signals the speaker has reasoned toward a conclusion rather than observed it directly.
It can also express requirement or obligation regarding identity or condition: The applicant must be at least eighteen.
- requiredNeeded by rule
- necessaryIndispensable, cannot omit
- obligatedRequired by duty
- essentialFundamentally necessary
- mandatoryRequired by rule
compelled · have to · ought to · need to · without fail · imperative · duty · bound · forced · do or die · come hell or high water · inevitable · unavoidable · certain · destined · written in the stars · commanded · demanded
- modal phrasescan do, will not, could have, might have, should have
- hedgessomewhat, I think, slightly, I believe, fairly