Like many other Western European languages, English historically allowed questions to be formed by inverting the positions of verb and subject. Modern English permits this only in the case of a small class of verbs ("special verbs"), consisting of auxiliaries as well as forms of the copula be. To form a question from a sentence which does not have such an auxiliary or copula present, the auxiliary verb do (does, did) needs to be inserted, along with inversion of the word order, to form a question. For example:

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