核心畫面
You can picture mettle as the material a person is made of. A piece of metal looks fine sitting on a table; only when you strike it do you find out whether it holds or bends. Mettle is that hidden hardness in a person, and a difficult situation is the strike that brings it into the open. That is why the word almost always arrives with testing attached to it.
可以想成：mettle 是一個人身上的材質。一塊金屬放在桌上，看起來都一樣，要敲下去才知道它硬不硬、會不會凹。人也是…更多收起
可以想成：mettle 是一個人身上的材質。一塊金屬放在桌上，看起來都一樣，要敲下去才知道它硬不硬、會不會凹。人也是這樣——順的時候看不出來，事情難起來的時候，裡面那塊材質才露出來。所以這個字幾乎都跟「測試」綁在一起：test your mettle、on your mettle，都是有東西正在敲你。From the word’s history
Mettle began simply as another spelling of metal, and from the 16th century English used it figuratively for the stuff a person is made of. The two spellings only came apart by meaning in the 18th century, leaving metal for the material and mettle for the person.
mettle 本來就是 metal 的另一種寫法。十六世紀開始，英文拿金屬來比喻人：這個人的材質好不好。到十八世紀，兩個拼法才依意思分家，metal 留給金屬，mettle 留給人。所以「敲下去才知道硬不硬」這個畫面，不是後來硬掰的比喻，而是這個字真正的來路。
Wiktionary 'mettle' etymology supplied in this packet (source_ref kaikki:3f6f69a190036ae4:840901769)
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。
mettlenoun/ˈmɛtəl/
- 1
A quality of courage and endurance.
- By this Day and this Light, the fellow ha's mettell enough in his belly.
- Please read on and discover the issues in education that test the mettle of those who experience this world every day.
- 2
Good temperament and character.
- Your Maſter quits you: and for your ſeruice done him, / So much againſt the mettle of your ſex
- The arrival of this unexpected heir soon taking wind in the court, still makes good for the Sol, and keeps the court upon its mettle.
mettleadj/ˈmɛtəl/
- 1
Spirited, vigorous, stout-hearted.
- And then one afternoon in the hinder end of April came young Heriotside riding to the Skerburnfoot. His arm was healed, he had got him a fine new suit of green, and his horse was a mettle beast that well set off his figure.
這個拼法也被記錄為下列字的變化形：
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。