hojo-keiyoushi 補助形容詞

In Japanese, hojo-keiyoushi 補助形容詞 are a type of auxiliary adjective that's attached to the te-form of verbs and the adverbial form of i-adjectives.

For example, in katte-hoshii 買ってほしい, "[I] want [you] to buy [this] for [me]," the word hoshii ほしい is a support adjective.

• List
• Grammar
• Orthography
• Things That Look Practically Identical, But That Are Actually Totally Different Things
• References

List

For reference, a list of support adjectives:

• ~te-hoshii
  ～てほしい
  [I] want [you] to do [the verb] for [me].

Yep. That's it.

That's the list.

It's literally just one single word.

This is such an absurd claim, I'm gonna have quote somebody down here just to make sure I'm not going insane and spewing random, baseless nonsense.

• te ni tsuduku hojo-doushi to hojo-keiyoushi (zensha wa "~te-iru" "~te-aru" "~te-oku" "~te-shimau" "~te-iku" "~te-kuru" to juju-doushi, kousha wa "~te-hoshii" nomi)
  テに続く補助動詞と補助形容詞（前者は「ている」「てある」「ておく」「てしまう」「ていく」「てくる」と授受動詞，後者は「てほしい」のみ）
  Support verbs and support adjectives that come after テ (the former is "~te-iru," "~te-aru," "~te-oku," "~te-shimau," "~te-iku," "~te-kuru," and giving-and-receiving verbs, the latter is only "~te-hoshii."
  • —Katou Shigehiro 加藤重広, 2007, page 111.

Yep. We are actually talking about undoubtedly just one single word. At most, two words, if you include nai ない, but that needs some explaining.

Grammar

Basically, most support expressions are hojo-doushi 補助動詞, "support verbs."

Among such support verbs, there's the verb aru ある, whose negative form is irregular: instead of aranai あらない, the negative of aru ある is the i-adjective nai ない.

• kaite-aru
  書いてある
  Written, [it] is.
• kaite-nai
  書いてない
  Written, [it] isn't.

Consequently, it can be said that this ~nai ～ない is a support adjective, or that it's the negative form of the support verb ~aru ～ある.

Besides this nai ない, the ONLY other support adjective is hoshii ほしい.

So the term hojo-keiyoushi is a mere counterpart of hojo-doushi used to accommodate these two words which aren't verbs, are adjectives, but work exactly like support verbs.

For example, you can insert the particles wa は and mo も between ~te ～て and hoshii ほしい.

• katte wa hoshii kedo
  買ってはほしいけど
  To buy [it], [I] want [you] to do for [me], but...
  I do want you to buy it for me, but...
  • See: contrastive wa は.
• katte mo hoshii kedo
  買ってもほしいけど
  To buy [it], [I] also want [you] to do for [me], but...
  I also do want you to buy it for me, but...

Manga: Komi-san wa, Comyushou desu. 古見さんは、コミュ症です。 (Chapter 5, 喋りたいんです。)

• Context: Tadano 只野 thinks about the school's most popular girl.
• Komi-san wa
  gakkou no madonna de mo
  hanashi-kake-dzurai bijin
  de mo nakatta.
  古見さんは学校のマドンナでも話しかけづらい美人でもなかった。
  Komi-san was neither the school's madonna
  nor a beautiful person [who's] hard to [approach].
  • hanashi-kakeru
    話しかける
    To approach and talk with. To start talking to. To begin a conversation with.
  • Very literally: to pour a conversation onto someone.

For details on grammar, just read the article about hojo-doushi 補助動詞 instead

Orthography

Orthographically, the normal adjective hoshii 欲しい can be spelled with kanji, but the support adjective hoshii ほしい, like other auxiliaries, and like support verbs, is normally spelled with hiragana.

• kore ga hoshii
  これが欲しい
  This is wanted.
  [I] want this.
  • See: double subject construction.
• kore wo katte-hoshii
  これを買ってほしい
  [I] want [you] to buy this for [me].

Things That Look Practically Identical, But That Are Actually Totally Different Things

There's a bunch of words that look like they would be hojo-keiyoushi, but aren't for some reason or another. For example:

• tsuki-atte-kudasai
  付き合ってください
  Please date [with me].

Above, kudasai ください is obviously a support expression, coming after the te-form of a verb. And it looks like an i-adjective. So is it a support adjective? No. It's actually a support verb, because kudasai ください is the ren'youkei 連用形 form of kudasaru くださる.

Next, the words ~yasui ～やすい and ~nikui ～にくい are similar to hojo-keiyoushi, but different. That's because they attach to the ren'youkei 連用形 form of verbs, not the te-form:

• kaki-yasui
  書きやすい
  Easy to write.

In this case, they would be called fukugou-keiyoushi 複合形容詞, "compound adjective," since their syntax is identical to the fukugou-doushi 複合動詞, "compound verbs," like naosu 直す, "to do again."

• kaki-naosu
  書き直す
  To write again. (because it was written wrong the first time.)

Another word that attaches in this way is the ~tai ～たい suffix, but ~tai ～たい isn't a fukugou-keiyoushi, it's a jodoushi 助動詞.

• kakitai
  書きたい
  [I] want to write.

The difference between ~tai ～たい and yasui 易い, "easy," nikui 難い, "difficult," and naosu 直す, "to fix," is that ~tai ～たい doesn't mean anything on its own: it's always a suffix, while the fukugou-keiyoushi and fukugou-doushi can be used as normal adjectives and verbs.

When ~nai ～ない is part of the negative form a verb, it's a jodoushi 助動詞, too.

• okane ga nai
  お金が無い
  [I] don't have money.
  • This is a normal adjective.
• yasukunai
  安くない
  [It] isn't cheap.
  • This is a hojo-keiyoushi.
  • Proof:
  • yasuku wa nai
    安くはない
    Cheap, [it] isn't. (this is a hojo-keiyoushi.)
• kirei de wa nai
  綺麗ではない
  Pretty, [it] isn't.
  [It] isn't pretty.
  • This is a hojo-keiyoushi, too, because this de で is the te-form of the copula da だ.
• wakaranai
  分からない
  [I] don't know.
  • This is a jodoushi 助動詞.
  • Proof:
  • *wakara wa nai
    分からはない
    (this is wrong grammatically.)

Some patterns look exactly like hojo-keiyoushi, but are actually separate clauses. For example:

• tabete ii?
  食べていい？
  To eat, good?
  Is it alright if I eat this?
• itsumo onaji koto itte urusai
  いつも同じこと言ってうるさい
  Every time, says the same thing, annoying.
  He keeps saying the same thing every time, it's annoying.

This happens because the te-form can be used as a conjunction, where the subordinate clause somehow leads to the matrix clause.

• mite odoroita
  見て驚いた
  See and be surprised.
  I saw that thing, and, subsequently, I was surprised.
  I was surprised when I looked at it.

So in the phrase tabete ii, we can say that tabete leads to ii. The only problem is that semantically the meaning of the word ii いい is an unholy mess. Basically, it means that it's good in the sense of it's not bad, and if it's not bad, it's alright, it's fine, it's allowed.

In other words, if the subordinate clause (tabete) leads to a good (ii), i.e. non-bad consequence, then the subordinate is allowed: is it okay to eat this? May I eat this? If I do eat this, won't you get sad? Or something like that.

Another situation is when an action expressed in the te-form is described by a predicate. For example:

• tabete wa dame
  食べてはダメ
  To eat is no-good.
  You shouldn't eat it.
  Don't eat that thing.
• tabecha dame
  食べちゃダメ
  (same meaning, contraction.)

In a case like above, dame ダメ is predicating the action tabete 食べて, so dame ダメ isn't a hojo-doushi either. Similarly, ikenai 行けない and naranai ならない, which can replace dame to mean the same thing, aren't support expressions, either. (see: ~te wa ～ては)

References

• 加藤重広, 2007. 日本語の述部構造と境界性. 北海道大学文学研究科紀要= The Annual Report on Cultural Science, 122, pp.97-155.