fukugou-keiyoushi 複合形容詞

In Japanese, fukugou-keiyoushi 複合形容詞, "compound adjectives," are adjectives composed of two words: a stem, and an adjective head suffixed to that stem.

For example: yomi-yasui 読みやすい, "easy to read," ii-nikui 言いにくい, "hard to say," kata-kurushii 堅苦しい, "formal," na-dakai 名高い, "famous," ao-jiroi 青白い, "bluish white, "pale," and chikara-dzuyoi 力強い, "strong," "reassuring," are all compound adjectives.

Grammar

The grammar of compound adjectives is almost the same as that of "compound verbs," fukugou-doushi 複合動詞, but there are a few very important differences worth noting.

Morphology

Like compound verbs, compound adjectives can have all sorts of stems.

hodo-tooi
程遠い
Very far from. Very distance to.
- A compound of tooi 遠い, "far," and the noun hodo 程, "extent."
ama-karai
甘辛い
Salty-sweet. Sweet and salty.
- A compound of karai 辛い, "salty," and the adjective amai 甘い, "sweet."
tettori-bayai
手っ取り早い
Quick.
- A compound of hayai 早い, "early," attached another compound, tettoru 手っ取る, which is a verb, toru 取る, "to take," attached to a noun, te 手, "hand." Literally: quick to take with one's hands.
usu-gimi-warui
薄気味悪い
Weird. Uncanny.
- A compound of warui 悪い, "bad, "with kimi 気味, "sensation," and usui 薄い, "thin," "faint." Literally something that gives you a faint, bad sensation. Something slightly creepy.
muzu-gayui
むず痒い
Itchy. (like there's something on your skin.)
- A compound of the base of the psychomimetic reduplication muzumuzu ムズムズ, *itch-itch,* as in, the sensation of itchiness on your skin, and kayui 痒い, which just means "itchy" in general.

Some compounds have antonyms which are composed of the same stem, except with the antonym of the suffix. For example:

kimochi-ii
気持ちいい
Feeling-good.
Pleasant.
kimochi-warui
気持ち悪い
Feeling-bad.
Unpleasant. Creepy. Disgusting, Disturbing.
kakko-ii
カッコいい
Appearance-good.
Cool.
kakko-warui
かっこ悪い
Appearance-bad.
Lame.

Like any other suffix, the suffixes of compound adjectives affected by changes in pronunciation like rendaku 連 and sokuonbin 促音便.

ao-guroi
青黒い
Blueish black.
- From aoi 青い, "blue," and kuroi 黒い, "black."
- The ku く became gu ぐ due to rendaku 連濁.

Some compound adjectives can be spelled with a single kanji instead.

aoguroi
黝い
Blueish black.
minikui
醜い
Ugly.
- From:
- mi-nikui
  見にくい
  Hard to look at.
- miru
  見る
  To see. To look at.
- nikui
  難い
  Difficult.

Intransitivization

Compound adjectives with verb stems have what appears to be a side-effect of changing the transitivity of the verb to intransitive.

For example, the verb tsukau 使う, "to use," is transitive: it has a subject and an object, the person using, and what's being used.

samurai ga katana wo tsukau
侍が刀を使う
The samurai uses the katana.

However, adjectives being, well, adjectives, they're kind of intransitive. The subject is the predicate, and that's it. There's no object. And instead of a normal verb, you have a copula linking subject and predicate together.

kono katana ga kirei da
この刀が綺麗だ
Pretty is true about this sword.
This sword is pretty.
- da だ - a copula.
kono katana ga yasui
この刀が安い
Cheap is true about this sword.
This sword is cheap.
- ~i ～い - a copulative suffix.

A compound adjective whose stem is a transitive verb works like an adjective, not like verb, and consequently won't have an object, it will have a subject, instead.

kono katana ga tsukai-yasui
この刀が使いやすい
Using-is-easy is true about this katana.
This katana is easy to use.

In the case above, the easy-ness of being able to perform an action is a psychological property of someone. Some people find this katana easy to use, other people don't. If we don't to say who feels such way, we have to mark that person as the subject.

This means we end up with two subjects, so we have a double subject construction.^{(Ohtani, et al., 2012:278)}

For example:

samurai ga {kono katana ga tsukai-yasui}
侍がこの刀が使いやすい
{Using-is-easy is true about this katana} is true about the samurai.
To the samurai, this katana is easy to use.

Since this is a double nominative construction, either subject can be marked by the wa は particle.

samurai wa kono katana ga tsukai-yasui
侍はこの刀が使いやすい
(same meaning, but the large subject is the topic.)
kono katana wa samurai ga tsukai-yasui
この刀は侍が使いやすい
(also same meaning, but the topic is the small subject, now.)

In the sentences above, we've only marked katana as a nominative subject, with the ga が particle, because we're working under the interpretation that tsukai-yasui is an adjective, not a verb.

This interpretation is, of course, correct, but there's a detail: tsukai is still transitive.

But if tsukai is still transitive, why is katana NOT marked by the wo を particle, which marks objects?

That's because katana isn't the object for tsukai. The word katana is the subject for the adjective phrase tsukai-yasui, which INCLUDES the verbal phrase tsukai, which is made out of just one word: the verb tsukai.

The stem verb is isolated from the rest of the sentence: it has no marked arguments, no object, no subject, no anything.

It's very important to note that, when words like yasui come after verbs, they aren't syntactically coming after verbs, after one word that's a verb, they're coming after verbal PHRASES, and turning the whole thing into an adjective.^{(Ikeya, 1992, as cited in Huang, 1997:8)}

This means that it's also possible to mark the would-be object with the wo を particle, but in this case the verbal phrase which the auxiliary adjective suffixes to is going to be different. Observe the examples below:

kodomo wa eikyou wo ukeru
子供は影響を受ける
Children receive influence. (literally.)
Children are influenced.
kodomo wa eikyou ga {uke}-yasui
子供は影響が受けやすい
Easy-{receiving} is true about influence is true about children.
As for children, influence is easily {received}.
Children are easily influenced.
- uke - a verbal phrase.
- uke-yasui - an adjectival phrase.
kodomo wa {eikyou wo uke}-yasui
子供は影響を受けやすい
Easy-{to receive influence} is true about children.
Children easily {receive influence}.
Children are easily influenced.
- eikyou wo uke - a verbal phrase.
- eikyou wo uke-yasui - an adjectival phrase.

In a case like above, the phrase marked with wo を is more common, since the phrase marked with ga が can be interpreted as emphasizing eikyou, "influence," with exclusiveness: children receive INFLUENCE easily, as opposed to guidance, for example, which they don't easily receive.

A phrase like samurai wa KANATA GA tsukai-yasui wouldn't make sense with wo を, because ga が makes tsukai-yasui exclusive of the katana, as opposed to other weapon, like the kunai, which a ninja would find easy to use instead.

It's also possible to use intensifiers with this adjectival phrase, just like you can use intensifiers with any other adjective.

kodomo wa totemo urusai
子供はとてもうるさい
Children are extremely annoying.
kodomo wa totemo {eikyou wo uke}-yasui
子供はとても影響を受けやすい
Children are extremely easy-{to receive influence}.
Children are extremely easily influenced.

In some cases, you wouldn't be able to use the intensifier with a verb, but you can use it with an adjectival phrase:

*kono hon wa totemo yomu
~~このはとても読む~~
(this doesn't make sense.)
kono hon wa totemo {yomi}-yasui
この本はとても読みやすい
This book is extremely easy-{to read}.

Lastly, note that there are some sentences where wo を can't be replaced by ga が, because the verb, and the auxiliary adjective, are in a separate subordinate clause. For example:

kono hon wo {{yomi-yasui} you ni} kaita
この本を読みやすいように書いた
[I] wrote this book {in a way that {is easy to read}}.
- In this sentence, hon is the object of the verb kaita, in the main clause, and not of yomi-yasui, in the subordinate clause. Consequently, we can't change wo を to ga が.

Other Auxiliaries

There are some words that look like fukugou-keiyoushi 複合形容詞, but are not. For example:

kono hon ga totemo {yomi}-tai
この本がとても読みたい
[I] really want {to read} this book.
- The ~tai ～たい suffix is a jodoushi 助動詞, not a fukugou-keiyoushi 複合形容詞.
- It's basically the same thing. Even the part where it turns an entire verbal phrase into an adjective.^{(Ikeya, 1996:159)}
- The only difference is that ~tai ～たい doesn't mean anything on its own, it's always a suffix. It's not a word, it's just a morpheme.
- Compound adjectives, on the other hand, are always composed of an adjective that means something on its own, for example:
- sore wa {yasui} koto da
  それは易いことだ
  That's something {easy}.
- *sore wa {tai} koto da
  それはたいことだ
  (wrong.)
kono hon wo yomi-nasai
この本を読みなさい
Read this book. (it's an order!)
- The ~nasai ～なさい suffix forms a fukugou-doushi 複合動詞, "compound verb," not a compound adjective.
- Although it ends in ~i ～い, it's not inflected like an i-adjective, like ~tai ～たい, instead, it comes from the verb nasaru なさる, "to do," like an abbreviation of the polite imperative nasaimase なさいませ.
kono hon wa yomi-sou da
この本は読みそうだ
This books, it seems like [he would] read.
- The ~sou ～そう suffix is a jodoushi 助動詞.
- Although sou そう can mean something on its own, it's inflected like a na-adjective, not like an i-adjective. Besides, what it means on its own is completely different from what it means as a suffix.