The short form of was not. You use it everywhere in speech and in friendly writing, with I, he, she, it and any singular thing: I wasn't ready, it wasn't my fault, she wasn't there. For you, we and they the matching word is weren't, because those take were.

of was not「was not」的 The short form簡短形式。You use it everywhere你到處都會用它，in speech and in friendly writing在口說和輕鬆的書寫裡，with I, he, she, it搭配 I、he、she、it and any singular thing和任何單數的東西：I wasn't ready我還沒準備好、it wasn't my fault不是我的錯、she wasn't there她不在那裡。For you, we and they對 you、we 和 they 來說，the matching word對應的字 is weren't是 weren't，because those take were因為它們用的是 were。

Two useful facts. First, wasn't is not lazy or wrong — it is what normal spoken English sounds like, and saying "was not" out loud makes you sound either very formal or very cross. English speakers say the full form on purpose when they want to press hard: "I was NOT lying." So the choice carries feeling, not just style.

Two useful facts兩件有用的事。First第一，wasn't is not lazy or wrong不懶惰也不算錯——it is what normal spoken English sounds like正常的英文口語聽起來就是這樣，and saying "was not" out loud而把 "was not" 整個唸出來，makes you sound會讓你聽起來 either very formal or very cross要嘛很正式，要嘛很生氣。when they want to press hard想要用力強調時，English speakers母語者 on purpose會故意 say the full form說完整形式："I was NOT lying.我「沒有」說謊。" So the choice所以這個選擇 carries feeling帶著情緒，not just style不只是文體。

Second, in careful writing — an exam essay, a report, a business letter — the full was not is the safer choice, because contractions look casual on paper.

Second第二，in careful writing在講究的書寫裡——an exam essay考試作文、a report報告、a business letter商業書信——the full was not完整的 was not is the safer choice是比較安全的選擇，because contractions因為縮寫 look casual on paper寫在紙上看起來隨便。

Wasn't also shows up in question tags, where it is extremely common and where learners in Taiwan most often meet it: "He was late, wasn't he?" and the reverse, "He wasn't late, was he?"

Wasn't also shows up也會出現 in question tags在附加問句裡，where it is extremely common它在那裡極為常見，and where learners in Taiwan most often meet it台灣的學習者也最常在那裡遇到它："He was late, wasn't he?他遲到了，對吧？" and the reverse以及反過來的 "He wasn't late, was he?他沒遲到，對吧？"