用左手的人，和為他做的東西
這一組就是核心畫面本身：先伸左手的人，以及因為他而被翻過來重做的東西。
adjective · B1
Using your left hand for most of the things other people do with their right hand — writing, throwing, cutting, holding a spoon — because that hand works better for you.
左撇子的；慣用左手的
核心畫面
You can picture left-handed as the left hand reaching first. In a world quietly built for the right hand, that one difference spreads outward: the person who reaches with the left, the tools that have to be rebuilt as mirror images for them, the turn that goes the other way round a screw, and — in one fixed American phrase — praise that does not arrive straight.
left-handed 可以想成「先伸出去的是左手」。而這個世界的東西，大多是安安靜靜照右手做的。所以這一個差別會一…更多收起
left-handed 可以想成「先伸出去的是左手」。而這個世界的東西，大多是安安靜靜照右手做的。所以這一個差別會一路往外擴：伸左手的人、必須整個做成鏡像的工具、跟螺絲反著轉的方向，還有一句美式固定說法裡「不是正著遞過來」的稱讚。From the word’s history
The source records left-handed as left + handed, appearing in Middle English as left handyd and lyfthonded. The word is literally the hand plus the side it is on, which is why every later use still starts from a direction.
資料把 left-handed 記成 left 加 handed，中古英文寫成 left handyd、lyfthonded。字面就是「手」加上「哪一邊」。所以後來每一種用法，起點都還是方向。
Wiktionary entry for left-handed (kaikki:3f6f69a190036ae4:521528147): 'From Middle English left handyd, lyfthonded, equivalent to left + handed.'
Three branches
跟平常相反的那個轉法
左手代表的不再是一隻手，而是「另一邊」這個方向本身。
adjective · C1
Turning or twisting to the left, the opposite way to an ordinary screw; also used in maths and science of a set of directions built as the mirror image of the usual right-handed one.
逆時針的；左旋的
不是正著遞過來的稱讚
這一組只活在一個固定片語裡，跟核心的關係是教學上的聯想，不是歷史上的來源。
adjective · C1
A left-handed compliment is something that sounds like praise but has an insult sitting inside it, so the person hearing it does not know whether to say thank you.
表面誇獎、其實在貶的話