照理說該這樣做
這一族比對的是「怎樣做比較合理」。結果落在人身上，所以聽起來像建議。兩支的差別在力道：一支在講明智，一支只是在丟一個好點子。
aux · B1
Used to say that someone should do something because it is the best or most sensible thing to do.
應該（這樣做比較明智）
核心畫面
Picture someone holding a situation up and measuring it against how things are meant to go. Ought to is the word for the gap between the two: this is how it lines up, so this is what follows. When the measure is what makes sense, what follows is advice. When the measure is right and fair, what follows is a duty. When the measure is what usually happens, what follows is not a duty at all but an expectation. The speaker is never forcing anything; they are pointing at the line and saying, that is where this should land.
可以想成有人把眼前的情況拿起來，對著「照理說該怎樣」比一比。ought to 就是那個比對的結果：照這條線看，答案應…更多收起
可以想成有人把眼前的情況拿起來，對著「照理說該怎樣」比一比。ought to 就是那個比對的結果：照這條線看，答案應該是這個。如果那條線是「怎樣比較明智」，比出來的就是建議。如果那條線是「怎樣才公平」，比出來的就是責任。如果那條線是「平常都是這樣」，比出來的就不是責任，而是預期。說話的人從頭到尾都沒有在逼誰，只是指著那條線說：這件事應該落在這裡。Three branches
這樣才公平
同樣是比對，但這次的那條線換成對錯與公平。線變重了，話就變重，雖然句子的樣子完全沒變。
aux · B1
Used to say that someone should do something, or that something should happen, because it is morally right or fair.
理應、應該（道義上）
照理說會是這樣
這一支把那條線從「該不該做」換成「平常都怎樣」。比出來的不是責任，而是預期，所以句子裡沒有人需要去做任何事。
aux · B1
Used to say that you think something will probably happen or is probably true, because that is what you expect from what you know.
應該會（推測）
原始詞典資料4 筆記錄
以下是外部詞典記錄的用法，原文照列，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。
ought toverb
- 1
Indicating duty or obligation.
- 2
Indicating advisability or prudence.
- 3
Indicating desirability.
- 4
Indicating likelihood or probability.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。