In linguistics, inverse copular constructions, named after Moro (1997), are a type of inversion in English where canonical SCP word order (subject-copula-predicative expression, e.g. Fred is the plumber) is reversed in a sense, so that one appears to have the order PCS instead (predicative expression-copula-subject, e.g. The plumber is Fred). The verb in these constructions is always the copula be (am, are, is, was, were). Inverse copular constructions are intriguing because they render the distinction between subject and predicative expression difficult to maintain. The confusion has led to focused study of these constructions,[1] and their impact on the theory of grammar may be great since they appear to challenge the initial binary division of the sentence (S) into a subject noun phrase (NP) and a predicate verb phrase (VP) (S → NP VP), this division being at the core of all phrase structure grammars (as opposed to dependency grammars, which do not acknowledge the binary division).