Is 眠たい an adjective?


I was told 眠たい was an adjective, and that it is an exceptional case. How does
it work as an adjective and what is its relation to the verb 眠る?




Yes, 眠たい is an adjective. It's a synonym of 眠い, meaning "sleepy." ([大辞泉 entry
here](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E7%9C%A0%E3%81%9F%E3%81%84&dtype=0&dname=0ss&stype=0&index=115203100000&pagenum=1).)

From what I can find (specifically, [大辞林's
explanation)](http://dic.yahoo.co.jp/dsearch?p=%E3%81%AD%E3%81%B6%E3%81%9F%E3%81%84&stype=0&dtype=0&dname=0ss),
眠たい is in fact related to 眠る, but the 「〜たい」 here is different from the
desiderative "I want to" 「〜たい」. This 「〜たい」 is a shortened form of 甚{いた}い (or
いたし, in its original form in older Japanese), which is a 連用形 verb ending in
classical Japanese meaning "extremely X, where X is the state related to the
verb." Here, this "state" is sleepiness. Note that this 甚{いた}い can attach to
verbs and give them an emphatic adjectival meaning, and does not attach to
adjectives.

めでたい (happy, fortunate) has a similar etymology: 愛{め}で (from the 連用形 of 愛{め}ず,
the old form of 愛する) ＋ 甚{いた}し.

Edit: Just to clarify, the original form of 眠たい was 眠{ねぶ}り甚{いた}し, but a
combination of phonetic drift and other factors led it to eventually evolve
into its current form.




Yes, 眠たい is an adjective. It's a synonym of 眠い, meaning "sleepy." ([大辞泉 entry
here](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E7%9C%A0%E3%81%9F%E3%81%84&dtype=0&dname=0ss&stype=0&index=115203100000&pagenum=1).)

From what I can find (specifically, [大辞林's
explanation)](http://dic.yahoo.co.jp/dsearch?p=%E3%81%AD%E3%81%B6%E3%81%9F%E3%81%84&stype=0&dtype=0&dname=0ss),
眠たい is in fact related to 眠る, but the 「〜たい」 here is different from the
desiderative "I want to" 「〜たい」. This 「〜たい」 is a shortened form of 甚{いた}い (or
いたし, in its original form in older Japanese), which is a 連用形 verb ending in
classical Japanese meaning "extremely X, where X is the state related to the
verb." Here, this "state" is sleepiness. Note that this 甚{いた}い can attach to
verbs and give them an emphatic adjectival meaning, and does not attach to
adjectives.

めでたい (happy, fortunate) has a similar etymology: 愛{め}で (from the 連用形 of 愛{め}ず,
the old form of 愛する) ＋ 甚{いた}し.

Edit: Just to clarify, the original form of 眠たい was 眠{ねぶ}り甚{いた}し, but a
combination of phonetic drift and other factors led it to eventually evolve
into its current form.

