2、去f，fe加ves，例如：half-halves、knife-knives、leaf-leaves、wolf-wolves、wife-wives、life-lives、thief-thieves。例句：1、I have three knives. “我有3把小刀。”2、There were forks, knives, spoons, and chopsticks.“他們是叉子，刀子，勺子和筷子。”3、I"m pricked and probed by what feels like knives, not needles.“我覺得這些針劑更像是刀子，它們在刺我、在戳我。”4、The stories I could tell you. Time and time again, how your knives have pulled my ass out of the fire.“我可以跟你講很多這樣故事，關於你們生產的刀是怎樣一次又一次的救我於水火之中。”
複數形式：knives。
以f或fe 結尾的名詞變複數時，有兩種方法：：1、加s，例如：belief-beliefs、roof-roofs、safe-safes、gulf-gulfs 。
2、去f，fe加ves，例如：half-halves、knife-knives、leaf-leaves、wolf-wolves、wife-wives、life-lives、thief-thieves。例句：1、I have three knives. “我有3把小刀。”2、There were forks, knives, spoons, and chopsticks.“他們是叉子，刀子，勺子和筷子。”3、I"m pricked and probed by what feels like knives, not needles.“我覺得這些針劑更像是刀子，它們在刺我、在戳我。”4、The stories I could tell you. Time and time again, how your knives have pulled my ass out of the fire.“我可以跟你講很多這樣故事，關於你們生產的刀是怎樣一次又一次的救我於水火之中。”