Although the middle construction has attracted significant attention from syntacticians, its identity still remains controversial and it is not treated as a separate grammatical category in any English learner＇s dictionary. This article, based on the data collected from three English learner＇s dictionaries, investigates the middle construction in terms of its syntactic and semantic properties and the constraints on its use. It shows that the three learner＇s dictionaries treat the middle construction in inconsistent and problematic manners. The middle use of a verb is not distinguished from either transitive verbs with an implicit object or intransitive verbs, which may hinder English learners＇ acquisition of the construction. The article proposes that middle verbs should be treated as a separate subcategory of verbs on a par with transitive and intransitive verbs so that learners will become more aware of them and learn to use them correctly.
