该短语是固定习语，通常用于口语或非正式语境，结构为：
主语 + eat one's words（one's 随主语变化，如 my/his/her/their 等）
可扩展为：eat one's words about sth（关于某事收回前言）/ eat one's words that...（收回“…的说法”）
1、 基础用法：
He laughed at my idea, but when it worked, he had to eat his words.
（他嘲笑我的想法，但当想法奏效时，他不得不收回前言。）
I said she couldn't finish the marathon, but she proved me wrong—I had to eat my words.
（我曾说她完不成马拉松，但她证明了我错了——我得承认自己说错了。）
2、 接 about sth：
She bragged about being the best, but after losing the competition, she had to eat her words about her skill.
（她吹嘘自己是最棒的，但比赛输了之后，她不得不收回关于“自己技术好”的说法。）
3、 接 that 从句：
The boss said that the project would fail, but when it succeeded, he had to eat his words that it was impossible.
（老板曾说项目会失败，但当项目成功时，他不得不收回“项目不可能完成”的说法。）
1、 复数 vs 单数：
更常见的是eat one's words（复数 words，因“言论”通常是多句话或观点），单数 "eat one's word" 较少见。
2、 易混淆短语：
不要和 "eat one's heart out"（极度悲伤、痛苦）混淆，如：He ate his heart out after his dog died.（他的狗死后，他悲痛欲绝。）
简言之，"eat one's words" 就是“打脸”的文雅说法——用事实让某人承认之前说错了话～