古い

From Old Japanese. Attested in the Man'yōshū completed in 759.^[1]

In turn, derived from verb 旧る (furu, “to age, to become older”, said of both things and people) + し (shi, Old and Classical Japanese adjective-forming suffix),^[2] with the verb itself also attested in the Man'yōshū.^[1][2]

The modern form furui emerged as a regular shift from furuki, the 連体形 (rentaikei, “attributive form”) of classical adjective 古し (furushi).

⟨puruki₁⟩ → */purukʲi/ → /furui/

• (Tokyo) ふるい (Nakadaka – )^[2][3][4][5]
• IPA^(key):

古(ふる)い • (furui) -i (adverbial 古(ふる)く (furuku))

1. (not of a person) old, aged, antiquated

   私(わたし)は以前(いぜん)古(ふる)いロールスロイスを持(も)っていた。

   Watashi wa izen furui Rōrusu-Roisu o motte ita.

   I used to own an old Rolls-Royce.

   私(わたし)は古(ふる)いランプを買(か)った。

   Watashi wa furui ranpu o katta.

   I bought an old lamp.

• 新(あたら)しい (atarashii, “new”)

• 古(ふる)い革袋(かわぶくろ)に新(あたら)しい酒(さけ)を盛(も)る (furui kawabukuro ni atarashii sake o moru, “to put new wine into old wineskins, to put new wine into old bottles”)
• 新(あたら)しい酒(さけ)は古(ふる)い革袋(かわぶくろ)に入(い)れる (atarashii sake wa furui kawabukuro ni ireru, “to put new wine into old wineskins, to put new wine into old bottles”)