其实不用纠结.无论是你想对I think做否定,还是he needs some help做否定,整个句子的变化结果都是I don't think he needs any help.当陈述部分的主语是I,谓语是think,believe,suppose,expect这类动词时,附加疑问部分...附加疑问部分则往往与从句中的主语和谓语动词保持对应关系，要注意否定是转移到这些词的。没太看懂，请举个例子吧，谢谢就是宾语从句动词的时态和逐句保持一致，否定句式加在think, believe, suppose, expect这类动词上而不是加在从句上的。所以无论是你想对I think做否定，还是he needs some help做否定，整个句子的变化结果都是I don't think he needs any help.