牙齿的英语怎么说单数

"tooth" 是牙齿的英语单数。这个词来自古英语 "tōth" 或 "tēth"，它在其他语言中也有类似的词汇，如德语 "Zahn"，法语 "dent"，拉丁语 "dens, dentis"。

例句：

I have a toothache. (我牙痛。)
She brushed her teeth twice a day. (她每天刷牙两次。)
The tooth fairy left a coin under his pillow. (牙齿仙女在他枕头下留下了一枚硬币。)