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English definition of “be not all there”

be not all there

informal
to be slightly stupid or strangeStupid and sillyOf unsound mind Grammar:AllSee moreGrammar:All as a determinerAll means ‘every one’, ‘the complete number or amount’ or ‘the whole’. We use it most often as a determiner. We can use a countable noun or an uncountable noun after it:See moreGrammar:All with no articleWhen all refers to a whole class of people or things, we don’t use the:See moreGrammar:All ofWe use all of before personal pronouns (us, them), demonstrative pronouns (this, that, these, those) and relative pronouns (whom, which). The personal pronoun is in the object form:See moreGrammar:All without ofWe use all, not all of, before indefinite plural nouns referring to a whole class of people or things:See moreGrammar:All with personal pronounsWhen all refers to a personal pronoun which is the object in a clause, we can use pronoun + all or all of + pronoun. The pronoun is in the object form:See moreGrammar:All as a pronounWe can use all alone as a pronoun in formal situations:See moreGrammar:All as an adverbWhen all refers to the subject of a clause, it usually comes in the normal mid position for adverbs (between the subject and the main verb, or after the modal verb or first auxiliary verb, or after be as a main verb):See moreGrammar:All meaning ‘completely’ or ‘extremely’We can also use all as an adverb meaning ‘completely’ or ‘extremely’, especially in informal styles:See moreGrammar:All: not allWe can make all negative by using not in front of it:See moreGrammar:All: after allWe use after all in two main ways. We use it to mean ‘in spite of what happened before’. With this meaning it usually occurs in end position:See moreGrammar:All or every?All and every are determiners.See moreGrammar:All and every + nounsThe meaning of all and every is very similar but we use them in different ways. We use all with plural and uncountable nouns and every with singular nouns:See moreGrammar:All (of) theWe can use all and all of before articles (the, a/an), demonstratives (this, that) and possessives (our, his) but we can’t use every before them:See moreGrammar:All day, every dayWe use all day, all week, all month to mean ‘one entire day/week/month’:See moreGrammar:All or every: typical errorsSee moreGrammar:All or whole?All and whole are determiners.See moreGrammar:All or whole for single entitiesWe use the whole or the whole of to refer to complete single things and events that are countable and defined:See moreGrammar:All the with uncountable nounsWe use all the and not the whole with uncountable nouns:See moreGrammar:All and whole with plural nounsWe usually use all the and all of the with plural nouns:See moreGrammar:All and whole: typical errorsSee more
(Definition of be not all there from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

Translations of “be not all there”

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