發生
這一族就是核心本身：事情發生、落到某人或某物身上。從「世界上發生了一件事」很自然延伸到「這件事影響到了誰」——同一個事件，只是把鏡頭從事件本身轉到被波及的人。
take place · verb · A2
When something happens, it takes place, usually without being planned.
發生
核心畫面
An event simply takes place — it comes about on its own, usually with nobody planning it.
可以想成：某件事「自己冒出來、發生了」，通常沒有人事先安排。核心畫面比較像一個事件就這樣落到世界上——不是誰刻意去做…更多收起
可以想成：某件事「自己冒出來、發生了」，通常沒有人事先安排。核心畫面比較像一個事件就這樣落到世界上——不是誰刻意去做，而是它就這麼來了。happen 後面那些「碰巧、剛好、這種事難免」的用法，都是從這個「事情自己發生」的底色長出來的：既然事情不是計畫好的，自然就帶著「湊巧、不由人」的味道。Three branches
碰巧、剛好
既然「發生」本來就帶著「不是計畫好的」這層意思，把它套到「你做某事」上，就自然變成「你剛好、碰巧做了某事」。這一族是把核心的「不由人安排」往「湊巧」的方向推。
happen to do (by chance) · verb · A2
If you happen to do something, you do it by chance, not because you planned it.
碰巧；剛好
固定片語裡的語氣用法
這些是把 happen 鑲進固定說法後磨出來的語氣或寒暄用法。底層還是「事情就這麼發生了」，只是說話的人借這個「不由人」的味道，來加強語氣、安慰別人、或問起舊人舊事的下落。
happen to (for emphasis) · verb · A2
Used to say something in a firm or slightly annoyed way, to make a point clear.
（語氣加強）就是；偏偏是
原始詞典資料6 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。
happenverb/ˈhæpən/
- 1
To occur or take place.
- Let me tell you how it happened.
- Seeing the British establishment struggle with the financial sector is like watching an alcoholic who still resists the idea that something drastic needs to happen for him to turn his life around.
- 2
archaicTo happen to; to befall.
- 'By my soul! I believe something bad has happened me,' he muttered, and popped up his window, and looked out, half dreaming over the church-yard on the park beyond […]
- 3
To do or occur by chance or unexpectedly.
- Take an umbrella in case it happens to rain.
- Do you happen to have an umbrella?
- 4
To encounter by chance.
- Unexpectedly, in a nook close by the farmhouse, he happened upon a spot where the vintage had actually commenced.
- 5
informalTo become popular or trendy.
happenadv/ˈhæpən/
- 1
obsoletedialectalmaybe, perhaps.
- Yeah, well happen if he'd gone quietly, she wouldn't have needed to show him who's in charge.
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。