- 1had not 的縮寫（多半用在過去完成：「那時還沒…／不曾…」）
Hadn't is the short, spoken form of had not. We use it with a past participle: She hadn't seen the film. That is the past perfect — you are standing in the past and looking at something even earlier. I hadn't eaten all day means: before that moment, I had not eaten. In writing, the stands in for the missing o in not. You will hear hadn't all the time in speech and informal writing. Though actually, in casual talk some people say hadn't where a textbook would want didn't or haven't, because all three feel like “not have.” They are not the same. Haven't is present perfect (up to now). Didn't is ordinary past. Hadn't is the “before then” one.
這個字是 had not 的口語縮寫，後面接過去分詞，句型是「hadn't + 過去分詞」，例如「She hadn't seen the film」。這是過去完成式：你站在過去的某一刻，回頭看更早發生的事。例如「I hadn't eaten all day」，意思是在那一刻之前，我整天都還沒吃東西。撇號代替的是 not 裡省掉的字母。
這個字在口語和非正式寫作中非常常見。在隨意的談話裡，有人會把該用 didn't 或 haven't 的地方換成 hadn't，因為三者聽起來都像「沒有」，但其實不同。haven't 是現在完成，指到現在為止；didn't 是一般過去式；hadn't 則是「在那之前」的意思。
組成had + n't. The n't is the short form of not. Older English had nought / naught, “no thing,” which later became the n't you hear in hadn't, haven't, and didn't.
原始詞典資料1 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
這個拼法也被記錄為下列字的變化形：
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。