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Phrase(s): (Someone’s) not supposed to.
Go to (It's) not supposed to., Phrase(s): (It’s) not supposed to. [and] (Someone’s) not supposed to.
a phrase indicating that someone or something is not meant to do something. (Often with a person’s name or a pronoun as a subject. See the examples.) • Fred: This little piece keeps falling off. Clerk: It’s not supposed to. • Bill: Tom just called from Detroit and says he’s coming back tomorrow. Mary: That’s funny. He’s not supposed to.
McGrawhill's American Idioms And Phrasal Verbs