陈述语气一般体现在主谓语序的变化。如：You are a student. (陈述）Are you a student? (疑问）句中如果有特殊疑问词，如what, where, when，why等一般要放在它引导的句子句首，不论是陈述还是疑问，也不论是宾语还是状语。如：What are you doing? I don't what you are doing now. 宾语放在句首也可以是陈述语气，表示强调。如： What he said I didn't understand. 这种用法多见于文学语言。所以你的句子 I know what they are looking for 是正确的。当然口语里也会出现例外，如： You're looking for what? 这是不规范的用法。
