とりたて詞の極性とフォーカス解釈

本稿はとりたて詞「も」「は」の統語的・意味的特徴を説明する新しい分析を提出する。「も」は否定文，「は」は肯定文において生起位置にとどまることができないが，この事実は「も」「は」が異なる極性素性を持つと想定することで説明される。また，否定文において「も」と「は」が異なるスコープ読みを持つ事実もこの「極性」の考えによって説明できる。先行分析と異なり，本稿はとりたて詞をフォーカスではなく「新情報」のマーカーであると考える。これにより，とりたて詞の統語的・意味的特徴がある種の節では見られなくなるという「節の非対称」もうまく扱うことができる。本稿の議論はフォーカス解釈の一般理論にも修正を迫ることになる。フォーカスは必ず広いスコープ読みを持ち，いわゆる再構築は適用しないと主張する*。

This paper argues that toritate particles mo and wa are licensed as focus by Agree with F(ocus). Since movement is not required for focus licensing, either particle can remain in its merged position. Several researches, however, have claimed that either mo or wa should undergo obligatory focus movement. Pointing out problems with their observations, I claim that obligatory movement takes place when Agree with F is otherwise blocked by an intervener. I assume that mo bears a [positive], and wa bears a [negative] polarity feature, and that Agree between F and mo/wa is blocked by an intervening polarity operator of the opposite value. It explains why mo has to move in a negative sentence, and wa in a positive sentence. The assumption of polarity features also explains scope interaction between toritate particles and negation (nai). Unlike previous analyses, I suggest that a focus phrase, which constitutes the final assertion of the sentence, should take the widest scope. It is therefore expected that either mo or wa takes scope over nai. The prediction apparently does not hold for wa, but the problem disappears once we take wa’s [negative] feature into consideration. What seems to be the denotation of nai is actually a realization of wa’s negative polarity meaning. Nai is contained in the assumption of the sentence, which means that wa as well as mo takes scope over nai. The suggested analysis also explains why the above properties of mo/wa are absent in some subordinate clauses. Those properties are assigned to a focus, but mo/wa is not licensed as focus when it fails to Agree with F.