过去式：swore；过去分词：sworn。例句：They swore their allegiance to the USA and received their naturalization papers.他们起誓忠诚于美国，随后就接到了批准他们入籍的文件。
swear的用法
swear的用法1：swear的基本意思是“咒骂”,指用污秽的语言对某人或某物进行攻击,造成精神上的伤害。swear还可指明确或郑重地向某人保证某事,即“发誓”。
swear的用法2：swear可用作及物动词,也可用作不及物动词。用作及物动词时,后接名词、代词、动词不定式或that从句作宾语,还可接以形容词充当补足语的复合宾语。可用于被动结构。
swear的用法3：swear表示“骂人”时,其后须与介词at连用。
swear的用法4：swear的过去式是swore,过去分词是sworn。
相关例句
1.He swore in Spanish, another indication that he was rattled.
他用西班牙语破口大骂，这再次表明了他极为烦躁。
2.Kelly swore quietly, looking at the deep cut on his left hand.
凯利看着自己左手上深深的伤口，嘴里暗骂了一句。
3.We both swore we'd be friends ever after.
我俩都发誓从此以后永远是朋友。
