Idiomatic each

Attempts have been made to argue that each other has a compositional interpretation and so each other indicates a reciprocal relation by virtue of what it means. Following Safir and Selvanathan (2017), I argue that the form each other is an idiom that serves as a morphological mnemonic for a relationship that is not composed from each other or any decomposition of each other. The real source of the reciprocal interpretation is a marker on the verb, silent in English, but overt in other languages. It is argued that each other is a morphological reflex in a concord relation to the silent affix. On this account, each other does not have any semantic content of its own, i.e., it is an idiom, as several sorts of arguments presented here reveal.