mine と my(所有代名詞)Mine and My: Owning With and Without the Noun
代名詞 / Pronouns
my は名詞とセット(my bag)、mine は単独で「私のもの」(That bag is mine.)。yours・his・hers・ours・theirs も同じ仕組みです。応用の頂点が a friend of mine(友達の一人)——my friend との違いまで分かれば、この項は卒業です。
My needs its noun (my bag); mine stands alone (That bag is mine). Yours, his, hers, ours, theirs all follow suit. The advanced move is a friend of mine — master how it differs from my friend and you've graduated.
名詞を連れた my、独り立ちの mine
My Brings the Noun; Mine Walks Alone
my は形容詞のように名詞の前に付き、単独では立てません。名詞をもう言いたくないとき、my +名詞をまるごと引き受けるのが mine です: "Whose umbrella is this?" "It's mine."(誰の傘? ——私の)。mine = my umbrella の圧縮形。同じ対が your/yours、her/hers、our/ours、their/theirs と続きます(his だけは両用)。
My works like an adjective: glued to its noun, never alone. When you'd rather not repeat the noun, mine absorbs the whole my + noun package: "Whose umbrella is this?" "It's mine." Mine = my umbrella, compressed. The same pairing runs through your/yours, her/hers, our/ours, their/theirs — with his pulling double duty.
圧縮形の出番The compressed forms at work
That seat is mine, and this one is yours.
その席が私ので、こっちがあなたの。
名詞の繰り返しを mine / yours が吸収。Mine and yours soak up the repeated noun.
My car is older than hers.
私の車は彼女のより古い。
比較でも大活躍(hers = her car)。Comparisons love them: hers = her car.
Aなぜ a なのか【初めて出す一つ】聞き手がまだ知らないものを初めて話に出すから a。次に同じものを指すときは the に変わる。 friend of mine lives in London.
友達の一人がロンドンに住んでいる。
紹介の定番形。下の解説へ。The introduction formula — see below.
my friend
聞き手も特定できる(例の)友達、または「私の友達」全般。文脈依存。The friend you both can place — or friends in general. Context decides.
I went to Kyoto with my friend Yuki.
友達のユキと京都に行った。
a friend of mine
「(何人かいる)友達のうちの一人」。初登場の紹介にちょうどいい。One friend out of several — perfect for first mentions.
A friend of mine works at that company.
友達の一人があの会社で働いてるんだ。
よくある間違い / Common Mistake
×"Whose phone is this?" "It's my."
「これ誰のスマホ?」「私の」(のつもりで)
○"Whose phone is this?" "It's mine."
「これ誰のスマホ?」「私の」
my は名詞なしでは立てません。日本語の「私の」は単独で言えるので、その感覚のまま my で止めるのが定番の事故。単独で答えるときは必ず mine / yours / hers の圧縮形です。
My can't stand without its noun. Japanese 私の works alone, and carrying that habit over is the classic slip. Standing alone, it must be the compressed forms: mine, yours, hers.
a friend of mine友達の一人a と my の席の衝突を of mine で回避した紹介の定番。The introduction formula born of the a-vs-my slot conflict.
The pleasure is mine.こちらこそ。「その喜びは私のもの」=お礼を返す上品な決まり文句。"The pleasure belongs to me" — the graceful return of thanks.
on my own自力で・一人でown は所有の強調役。by myself と同義の相棒。Own intensifies possession — by myself's twin.
mind your own business余計なお世話だ「自分の用事の面倒を見ろ」。own の突き放し力が効いた慣用。"Tend to your own affairs" — own, at full push-back strength.
まとめ / Summary
my +名詞/ mine 単独。yours・hers・ours・theirs も同じ対。My + noun; mine alone — with yours, hers, ours, theirs in step.
単独の答えは必ず圧縮形(It's mine.)。Standing answers take the compressed form: It's mine.
a friend of mine =友達の一人(紹介の定番)。A friend of mine: one of my friends — the introduction formula.
a と my は同じ席に置けない。of mine で迂回する。A and my can't share the slot — of mine is the detour.