や

1. や is used to combine two or more nouns or noun phrases. It cannot be used to combine predicates. Thus, (1) is unacceptable.

(1) *きのうはデパートに行きましたや映画を見ました。 Yesterday I did things like going to a department store and seeing a movie.

Instead of (1) we have to use たり~たりする to express an inexhaustive listing of predicates, as in (2).

(⇨ たり~たりする)

(2) きのうはデパートに行ったり映画を見たりしました。

2. NounやNoun can be used as a noun phrase in any position where a single noun can be used. It can be used as the subject, as in Key Sentence and Example (a), or as the direct object as in Example (b), or as the indirect object as in Example (c).

3. NounやNoun cannot appear in the position of X in the XがYだ construction, because が in XがYだ is a highly exhaustive listing marker.

(⇨ が1)

(3) *ジェーンやミッシェルが学生です。 *Jane and Michelle and only they (and others) are students.

This idea can be conveyed using the construction in (4):

(4) 学生はジェーンやミッシェルです。 The students are Jane or Michelle (and others).

【Related Expression】

とか is used to make a rather general, inexhaustive listing of items as examples, whereas や is used to make an inexhaustive listing of items related to a specific time and place. Consider the following examples:

[1]

(a)
• A: スミスさんは例えばどんな日本食が好きですか。
• Mr. Smith, what kind of Japanese cuisine do you like? Give me some examples.
• B: そうですね。てんぷらとか/?やすきやきとか/?や刺身ですね。
• Well,I'd say tempura, sukiyaki and sashimi (and others).

(b)
• A: きのう料理屋で何を食べましたか。
• What did you eat at the Japanese restaurant?
• B : てんぷらや/???とかすきやきや/???とか刺身を食べました。
• I ate tempura, sukiyaki and sashimi (and others).