事情或人容易往哪邊走
這一家是核心本身，再把時間拉長看：一次的偏向是 tendency，很多人很多年的偏向累積起來就是 trend 那個層次的 tendency。
inclination · noun · C1
The way someone or something is likely to do a certain thing, or to become a certain thing.
傾向
核心畫面
A steady lean in one direction. Nothing has happened yet, but the pull is already there — leave it alone and this is the way it will go.
一個一直往同一邊傾的斜坡。東西還沒滾下去，但只要放著不管，它會往哪邊走已經很清楚了。tendency 講的就是這股「…更多收起
一個一直往同一邊傾的斜坡。東西還沒滾下去，但只要放著不管，它會往哪邊走已經很清楚了。tendency 講的就是這股「還沒發生、但已經在那裡的偏向」——某個人容易怎麼做、某件事容易變成什麼樣。注意它從來不是「一定會」：斜坡只是讓某個方向比較容易，不是保證。所以英文說 He has a tendency to be late，是「他很容易遲到」，不是「他每次都遲到」。From the word’s history
From Medieval Latin tendentia, from Latin tendere — to stretch, to stretch out toward. The same root gives extend, intend, tension: something is being pulled taut in a particular direction.
這個字來自中世紀拉丁文 tendentia，源頭是拉丁文 tendere——「拉伸、朝某個方向伸展」。同一個根長出 extend（往外伸）、intend（心往某處伸＝打算）、tension（被拉緊的張力）。看懂 tendere，tendency 的畫面就出來了：有一條看不見的線正把某樣東西往某個方向拉。不是已經到了，是正被拉著。這也解釋了為什麼這個字總帶著「方向感」而不是「結果」——拉力可以被抵抗，只是不抵抗的話就會順著走。
Wiktionary, "tendency" (English noun): from Medieval Latin tendentia < Latin tendēns, present participle of tendō ("I stretch, extend, aim")
Three branches
長在一個人身上的性情
把那股拉力從「這件事」收進「這個人是誰」——不是偶爾偏一下，是體質裡就帶著這個斜度。
personal trait · noun · C1
A part of who someone is that makes them likely to act in a certain way, or to grow into a certain kind of person.
癖性
政治團體裡往更遠處拉的那一支
把「往某個方向拉」具體化成一群人：他們就是黨內那股一直往外拉的力量，久了自成一派。
political faction · noun · C1
A smaller set of people inside a party or movement who push ideas further than the main group does.
派系
原始詞典資料2 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。
tendencynoun/ˈtɛn.dən.si/
- 1
A likelihood of behaving in a particular way or going in a particular direction; a tending toward.
- Denim has a tendency to fade.
- I have a tendency to get bored after the first half an hour of a movie.
- 2
governmentpoliticsAn organised unit or faction within a larger political organisation.
- Mao launched the struggle against the vulgar materialist tendency within the party as early as 1937.
- In stark contrast to the Europeanist tendency within the party and the Suez Group, this group had a short history.
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。