你來我往（彼此對彼此）
這一組直接就是核心畫面：兩邊互相給同一樣東西。
mutual respect · adjective · C1
A feeling such as respect or trust that two or more people have for each other equally.
相互的 / 彼此的
核心畫面
You can picture 'mutual' as something that goes both ways — passed back and forth between two people, not just one-directional. Whatever it is (respect, help, a decision), each side gives it to the other, so it bounces in both directions at once.
mutual 可以想成「兩邊互相來回」的東西——不是只有一方給，而是在兩個人之間你來我往地傳。不管傳的是什麼（尊重、…更多收起
mutual 可以想成「兩邊互相來回」的東西——不是只有一方給，而是在兩個人之間你來我往地傳。不管傳的是什麼（尊重、幫助、一個決定），每一方都同時給對方，所以它是雙向同時發生的。From the word’s history
From Latin 'mutuus' = 'reciprocal, done in exchange', from the PIE root *mei- 'to change, exchange'. The idea of things swapped back and forth is exactly the modern core: mutual = given in both directions.
來自拉丁文 mutuus，意思是「相互的、彼此交換的」，源自更古老的字根 *mei-（改變、交換）。這種東西被來回交換的意象，正好就是今天的核心：mutual＝雙向互給。
Online Etymology Dictionary (etymonline.com/word/mutual)
Two branches
共同擁有的
從「你來我往」再走一步：既然兩邊都連著同一樣東西，那樣東西就成了兩人共有的。焦點從「互相給」滑到「共同有」。
shared by both · adjective · C1
Belonging to or shared by both of two people.
共同的
原始詞典資料8 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。
mutualadj/ˈmjuːt͡ʃuəl/
- 1
Having the same relationship, each to each other.
- They were mutual enemies.
- 2
Collective, done or held in common.
- Mutual insurance.
- 3
Reciprocal.
- They had mutual fear of each other.
- 4
Possessed in common.
- They had been introduced by a mutual friend.
- On his area the pursuer built a dwelling-house, of which the gable and garden-wall were mutual with his neighbour Smith […]
- 5
businessfinanceinsuranceOwned by the members.
mutualnoun/ˈmjuːt͡ʃuəl/
- 1
A mutual fund.
- 2
businessfinanceinsuranceA mutual organization.
- 3
Either of a pair of people who follow each other's social media accounts.
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。