The use of grammatical gender in the Australian language Mawng calls into question prevailing ideas about the functions of nominal classification systems. Mawng’s gender system has a strong semantic basis and plays an important role in the construction of meaning in discourse. Gender agreement in verbs is frequently lexicalized, creating idioms called lexicalised agreement verbs that are structurally similar to noun-verb idioms. This book will be of interest to anyone interested in nominal classification or cross-linguistic approaches to idioms.