its と it's(アポストロフィの罠) Its or It's? The Apostrophe Trap
代名詞 Pronouns
its =「それの」(所有・アポストロフィなし)、it's = it is / it has の縮約(アポストロフィあり)。ネイティブが最も多く間違えるスペルの一つです。判定は一発: it is(または it has)と読み替えて意味が通るなら it's、通らないなら its。
Its means "belonging to it" — no apostrophe. It's is the contraction of it is or it has — apostrophe required. It's one of the most common misspellings among native writers. The one-step test: expand it to it is (or it has). If the sentence survives, write it's; if not, its.
読み替えテスト一発で決まる
One Expansion Test Settles It
The dog wagged its tail.(犬がしっぽを振った)——「犬が it is tail を振った」は意味不明なので its。It's raining.(雨だ)——「It is raining」で通るので it's。迷ったら毎回この読み替えをやるだけです。発音は同じなので耳では区別できません。書くときだけの罠です。
The dog wagged its tail — "the dog wagged it is tail" is nonsense, so its. It's raining — "it is raining" works, so it's. Run the expansion every time you hesitate. The two are pronounced identically, so your ear can't help you; this trap only exists on paper.
読み替えテストの実演 The test, demonstrated
The company changed its logo.
その会社はロゴを変えた。
「it is logo」は不成立 → its(所有)。 "It is logo" fails — its, possession.
It's been a long day.
長い一日だった。
It has been で成立 → it's(it has の縮約)。 "It has been" works — it's, contracting it has.
Every country has its own customs.
どの国にも、その国なりの習慣がある。
its own(それ自身の)は頻出コンビ。 Its own is a high-frequency pair.
its
所有。「それの」。my・his の仲間。 Possession — "of it." Family of my and his.
The app lost most of its users.
そのアプリはユーザーの大半を失った。
it's
縮約。it is / it has の圧縮形。 Contraction — it is or it has, squeezed.
It's the best app I've used.
今まで使った中で最高のアプリだ。
よくある間違い Common Mistake
The bird spread it's wings.
鳥が翼を広げた。(のつもりで)
The bird spread its wings.
鳥が翼を広げた。
「it is wings を広げた」は不成立なので its です。「所有には 's」という英語の一般則(the bird's wings)に引っ張られるのがこの罠の正体で、ネイティブの書き間違いも大半がこのパターン。its だけは 's なしの所有、と例外を体に入れてください。
"Spread it is wings" fails the test — its. The trap works because English usually marks possession with 's (the bird's wings), and most native slips follow exactly that pull. Its is the exception: possession with no apostrophe. Drill it in.
- it's been a while 久しぶり この it's は it has。縮約は is だけでないことを体感できる定番。 This it's is it has — proof the contraction covers more than is.
- on its own それ単体で・ひとりでに 「それ自身の力で」。所有の its の頻出コンビ。 "By its own power" — possessive its at its busiest.
- at its best 最高の状態で 「それの最良の姿で」。批評・紹介文の常連。 "In its finest form" — a staple of reviews.
- It's about time. やっとか/そろそろ潮時だ。 it is の縮約。待ちくたびれた気持ちを載せる定番。 It is, contracted — with a sigh of "finally" built in.
まとめ Summary
- its =所有(アポストロフィなし)、it's = it is / it has。 Its = possession, no apostrophe. It's = it is / it has.
- 判定は読み替えテスト: it is で通るか? The test: does it is survive the swap?
- 所有代名詞の一族(hers・yours・theirs)は 's を取らない。 The pronoun family — hers, yours, theirs — never takes 's.
- ネイティブも間違える罠。書くときだけ注意すればいい。 Natives trip here too — and only on paper.