Linguistics PhD candidate Andrew McInnerney has authored a paper titled "Parenthetical Niching: A Third-Factor Phonosyntactic Analysis." The paper is currently in press with the journal Syntax.

Parentheticals (such as ‘I think’ or ‘as you know’) are words and phrases that often seem to be semantically and prosodically independent of the host utterance in which they appear. This paper asks where in a given sentence a parenthetical can be inserted, or 'niched.' The paper proposes that 'niches' are defined in terms of prosodic structure, such that parentheticals can occur at positions in a given host sentence where prosodic boundaries occur, and develops an account of how that follows naturally if we assume that parenthetical-host constructions have the structure of two syntactically separate sentences. 

Andrew developed the paper under the supervision of his advisor Sam Epstein (1956-2019), who passed away while the paper was under review. The paper was accepted for publication in October 2020. 

ABSTRACT

In this paper, I develop a theory of how a syntactically unintegrated parenthetical is integrated with its host at the Sensorimotor interface (SM). First, I observe that the niches open to parentheticals, traditionally described in syntactic terms, are more accurately described in the terms of Prosodic Hierarchy Theory. In particular, I show that a niche corresponds to a phonological phrase boundary. I then argue that this follows if a parenthetical is constructed in a separate syntactic workspace, and is integrated with its host at SM (without ever being integrated in Narrow Syntax) in a manner that is constrained by (i) certain properties of the syntactic workspace, (ii) the No Tampering Condition, and (iii) certain properties of the syntax-phonology mapping.