In this talk, I will examine the properties of particle ellipsis in Japanese in hopes of discovering some general principles governing the distribution of focus.

The nominative case particle in Japanese (ga) is omissible under certain circumstances, as in the sentence Taiyoo (ga) detekita 'The sun came out'. The descriptive goal of this talk is to determine exactly under what circumstances the particle is allowed to be absent. Authors such as Tsutsui, Tateishi, and Kageyama have made claims such as the following:

• The particle is harder to drop when it marks an agentive NP.
• The particle is harder to drop when it marks the subject of an individual-level predicate.
• The particle is harder to drop when the particle is not adjacent to a predicate.

These seem to be fairly adequate descriptions of observed tendencies, but there are exceptions to each of these generalizations, as has been pointed out in the previous literature.

In this talk, I will first argue that particle ellipsis in Japanese is subject to what I will call the Antifocus Constraint, a constraint which prohibits ellipsis of a particle when either the NP marked by that particle or its head noun is focused. (An expression is said to be focused when it is interpreted as contrasting with some other object of the same type.) Then, making use of some intonational facts noted by Selkirk, Tateishi, Kori, and others, I will argue that the Antifocus Constraint alone captures all the facts that the three generalizations listed above are intended to capture. In other words, it will be my claim that the distribution of focus within a sentence (and not just the distribution of prosodic prominence) is affected by the internal semantic makeup of the sentence.