動詞：持刀刺人
把名詞直接當動詞用，動作比較像「把刀送進去」。英文很常這樣把工具變成動詞，像 hammer、brush 也是同一種轉法。
knife, stab · verb · A1
To hurt or attack someone by pushing a knife into their body.
持刀刺傷
核心畫面
Picture a thin metal blade with an edge on it and a handle to hold it by. In your hand it goes through things that would otherwise resist — bread, rope, skin. Everything else this word does comes from those two facts: it cuts easily, and pointed at a person it hurts.
可以想成：一片薄薄的金屬，一邊開了刃，後面接著握把。拿在手上，本來切不開的東西就分開了——麵包、繩子、皮膚。這個字後…更多收起
可以想成：一片薄薄的金屬，一邊開了刃，後面接著握把。拿在手上，本來切不開的東西就分開了——麵包、繩子、皮膚。這個字後面所有的用法都從這兩件事長出來：它切得很輕鬆，而且對著人就會傷人。英文有一整組跟刀有關的固定說法，都是把這個畫面搬到人際關係上。From the picture
固定說法：把刀對著人
這一組把刀從廚房搬到人際關係上：真正的刀沒有出現，但「有人要對付你」「傷口被再攪一下」的畫面很清楚。三個說法都是整串固定的，也都屬於口語。
the knives are out for someone · noun · A1
If the knives are out for someone, people are ready to criticize or attack them strongly, often to make them lose their job or place.
群起圍攻
固定說法：手術刀底下
這裡的刀換成了手術刀，人躺在下面。刀還是那把會切開身體的刀，只是這次拿刀的人是在幫你。
under the knife · noun · A1
If someone is under the knife, they are having a medical operation.
開刀；動手術
固定說法：拿刀的鋒利當比喻
這一組用的不是刀的危險，而是刀切東西的手感：有的東西厚重到刀都切得動，有的東西軟到刀一下去就過去了。兩句都是整串固定的口語說法。
you could cut the atmosphere with a knife · noun · A1
Used to say that the people in a place felt so tense or unfriendly that you could almost feel it in the air.
氣氛緊張到極點
Also in this word
knife (tool) · noun · A1
A tool with a sharp metal blade and a handle, used for cutting things such as food.
刀；小刀
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。
knifenoun/ˈnaɪ̯f/
- 1
A utensil or a tool designed for cutting, consisting of a flat piece of hard material, usually steel or other metal (the blade), usually sharpened on one edge, attached to a handle. The blade may be pointed for piercing.
- He was looking for a knife to chop some steak.
- Jeff was bent low over the backboard, working with the knife, a steady sawing motion, his shirt soaked through with sweat.
- 2
A weapon designed with the aforementioned specifications intended for slashing or stabbing but too short to be called a sword; a dagger.
- 3
Any blade-like part in a tool or a machine designed for cutting, such as that of a chipper.
knifeverb/ˈnaɪ̯f/
- 1
To cut with a knife.
- 2
To use a knife to injure or kill by stabbing, slashing, or otherwise using the sharp edge of the knife as a weapon.
- She was repeatedly knifed in the chest.
- One day his sergeant began to cane him, on which, seizing his knife, he knifed the sergeant : he knifed the privates : he knifed until he was finally overpowered, and, brought before a court-martial, was condemned to fifteen years at the galleys.
- 3
To cut through as if with a knife.
- The boat knifed through the water.
- 4
To betray, especially in the context of a political slate.
- 5
To positively ignore, especially in order to denigrate; compare cut.
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。