2020年7月英语六级第1套真题句子解析： What the protagonist did not know was that an antagonist had come and messed with his possessions.

What the protagonist did not know was that an antagonist had come and messed with his possessions.

本句存在两层嵌套：第一层是主语从句"What the protagonist did not know"，整个作为主句的主语；第二层是表语从句"that an antagonist had come and messed with his possessions"，嵌套在主句内部作表语。主语从句内部还包含一个否定的谓语结构"did not know"，表语从句内部包含并列谓语"had come and messed"。这种从句套从句的结构形成了两层嵌套，是典型的名词性从句嵌套模式。

had come and messed

"had come"和"(had) messed"是两个谓语动词，由对等连词"and"连接，共享同一个主语"an antagonist"和同一个助动词"had"。这两个谓语表达了先后发生的两个动作：对手来了，并且弄乱了主角的物品。虽然第二个谓语省略了助动词"had"，但从语法结构看，这是典型的并列谓语结构，属于分句级（clause-level）的并列，符合并列句的定义。

What the protagonist did not know was

伪分裂句（Pseudo-cleft sentence）是一种强调句型，通过 "What + 从句 + be 动词" 结构将想要强调的信息置于句尾焦点位置。

识别要点：what 引导的名词性从句必须在系动词之前作主语，系动词后的成分是被强调的核心信息。本句中 "What the protagonist did not know" 整体作主语，"was" 是系动词，其后的 "that an antagonist had come and messed with his possessions" 是被强调的内容。

与普通陈述句对比：原句可改写为 "The protagonist did not know that an antagonist had come and messed with his possessions"，但伪分裂句通过倒装结构将 that 从句放到句尾，制造悬念和强调效果。

判定方法：检查 what 从句是否在系动词之前（作主语），若 what 从句在系动词之后则是表语从句，不属于伪分裂强调。本句符合 "what 从句作主语 + be 动词 + 焦点信息" 的完整结构。

翻译策略：中文可译为 "主人公不知道的是……" 或 "……这是主人公不知道的"，保留强调焦点在句尾的效果。