本研究では、日本語の複数形態素「-たち」と、数詞「一」を含む数量表現について特徴を考察した。これまで、英語の-sは〈正常複数〉、「たち」は〈関連複数〉であるとされてきた。それに対し本研究では、これらの複数形態素の機能を個体の同質化として仮定することにより〈正常複数〉に統合されることを主張した。そして、〈関連複数〉の意味は、〈正常複数〉の形式から〈関連性〉が含意される場合にのみ生じるものとして説明可能であることを示した。これは、人間言語に２種類の〈複数〉は存在しないというCorbett (2000)の主張を支持するものである。次に、数詞「一」を含む数量表現について、それらが意味論的には英語の不定冠詞と同様、数量表示・個体指示・種族表示の機能を担う名詞句内で用いられることとを主張した。そして、この状況が数詞「一」および不定冠詞の文法化に関する言語普遍性(Givón 1981)と一致することを確認した。
This dissertation examines some properties of Japanese numerical expressions which indicate plurality and singularity of nominals. First, I argue that the Japanese plural morpheme -tachi and its English equivalent -s mark the same kind of plurality. It has been claimed that human languages have realized two different plurals: (1) ordinary plurals (ORD-PL) such as boys referring to a group comprised of more than one boy and (2) associative plurals (ASSOC-PL) such as we referring to a group comprised of the speaker and others. -tachi has been assumed to be different from -s because the former is ASSOC-PL, while the latter is ORD-PL. However, the difference will disappear if some semantic properties are taken into consideration. When individuals are homogeneous, the two types of plurality are unified into one, i.e. ORD-PL, because ASSOC-PL is realized only when associativity is implied in the form of ORD-PL. The implication arises when individuals are heterogeneous and integrated into one group based on non-linguistic information such as speech roles and scripts. On the other hand, there's no such implication when individuals are heterogeneous but integrated into one group based on linguistic information such as categories represented by a base noun. This view supports the linguistic universal which claims that human languages realize ORD-PL only (Corbett 2000). Second, I argue that the English numeral one and its Japanese equivalents are similar in their uses. English is known to have an indefinite article a(n), which is a cognate to one, but Japanese has been assumed to have no such thing. However, a(n) and Japanese numerical expressions which corresponds to one behave similarly within NP. Both appear with a noun in the following environments: (1) quantification indicating singularity of the noun, (2) denotation referring to an individual, and (3) connotation standing for genericity of the noun. This view supports the linguistic universal which claims that if a numeral one, or an indefinite article, in a language has the connotational use, it has the other two uses as well (Givón 1981). This is because the English numeral one and its Japanese equivalents are semantically alike in their uses.