Are foreign adjectives always な adjectives?


Sitting in a restaurant yesterday I saw a sign advertising a mango flavoured
bagel. It was described as `トロピカルな味`.

That just got me wondering... whenever a `外来語【がいらいご】(word taken from a foreign
language / "loan word")` is used as an adjective, is it always a `な`
adjective?

Are there any examples of loanword `い` adjectives?

Are there any general guidelines as to how loan words are made to conform to
Japanese adjective rules.

_(Please note I'm not familiar with linguistics, so even though I'm asking a
fairly technical grammatical question, please dumb it down for me as much as
possible. Thanks!)_




If you're OK with エロい (as discussed in comments), there are examples like:

  * エロい
  * グロい
  * ナウい

But note that these are directly derived from エロ(チシズム), グロ(テスク), and ナウ
("now"). They were not borrowed into the language as -i adjectives; they were
borrowed into the language as nouns and/or na adjectives, and then THOSE
borrowings were turned into -i adjectives. Ultimately, this is a form of
slang/language play along the lines of the verbs タクる for "take a taxi", マクる
for "eat at McDonalds", etc.

So, to get back to the original question, yes. Foreign adjectives always start
out as な adjectives. This is a clear rule in Japanese dating from the days of
strong Chinese influence. Even when the borrowed word actually ends in an -i
sound (e.g. ファジー, セクシー), it is still treated as a な adjective when it first
arrives in Japanese. But, once they are in the language, they _can_ be broken
down and then reborn as -i adjectives, a la グロい.

The interesting issue, I think, is: how "real" are these 二世 -i adjectives? On
one end of the scale, I think that エロい and グロい are completely unremarkable now
in colloquial Japanese. No-one thinks of them as wordplay. At the other end of
the scale, I have heard things like セクシくない, but _only_ as a joke. Treating
セクシー is if it were セクシい, an -i adjective, even though both speaker and
listener know that it is not, is unexpected and therefore amusing. Sort of
like how in English we might say "You think that's amazing? I can show you
something even amazinger!" even though we know that "amazing" doesn't take the
"-er" ending.

(Tangent: Note that セクシい is structurally different from グロい: instead of taking
the first two morae and making a new stem, it just reinterprets (intentionally
misinterprets) the existing sounds of the word セクシー. This may be one reason
why セクシい remains at gag level while グロい is already a regular word. Maybe the
_only_ way to create unremarkable adjectives/verbs from gairaigo in Japanese
is to create a two-mora stem and build on that, and any other method will
always remain at the humorous level. I haven't looked into this too deeply. It
would be especially interesting to look at perceptions of these words among
people born before and after they were created.)




If you're OK with エロい (as discussed in comments), there are examples like:

  * エロい
  * グロい
  * ナウい

But note that these are directly derived from エロ(チシズム), グロ(テスク), and ナウ
("now"). They were not borrowed into the language as -i adjectives; they were
borrowed into the language as nouns and/or na adjectives, and then THOSE
borrowings were turned into -i adjectives. Ultimately, this is a form of
slang/language play along the lines of the verbs タクる for "take a taxi", マクる
for "eat at McDonalds", etc.

So, to get back to the original question, yes. Foreign adjectives always start
out as な adjectives. This is a clear rule in Japanese dating from the days of
strong Chinese influence. Even when the borrowed word actually ends in an -i
sound (e.g. ファジー, セクシー), it is still treated as a な adjective when it first
arrives in Japanese. But, once they are in the language, they _can_ be broken
down and then reborn as -i adjectives, a la グロい.

The interesting issue, I think, is: how "real" are these 二世 -i adjectives? On
one end of the scale, I think that エロい and グロい are completely unremarkable now
in colloquial Japanese. No-one thinks of them as wordplay. At the other end of
the scale, I have heard things like セクシくない, but _only_ as a joke. Treating
セクシー is if it were セクシい, an -i adjective, even though both speaker and
listener know that it is not, is unexpected and therefore amusing. Sort of
like how in English we might say "You think that's amazing? I can show you
something even amazinger!" even though we know that "amazing" doesn't take the
"-er" ending.

(Tangent: Note that セクシい is structurally different from グロい: instead of taking
the first two morae and making a new stem, it just reinterprets (intentionally
misinterprets) the existing sounds of the word セクシー. This may be one reason
why セクシい remains at gag level while グロい is already a regular word. Maybe the
_only_ way to create unremarkable adjectives/verbs from gairaigo in Japanese
is to create a two-mora stem and build on that, and any other method will
always remain at the humorous level. I haven't looked into this too deeply. It
would be especially interesting to look at perceptions of these words among
people born before and after they were created.)

