区别在于最终的怀疑的结果不同。
1、suspect的意思是“疑为是”；doubt的意思是“疑为非”。例如：I doubt that she is the criminal。我不相信她是罪犯。(认为不见得)。I suspect that she is the criminal。我怀疑她是罪犯。(认为有可能)
2、suspect举例：The above complaints are, I suspect, just the tip of the iceberg。我想，以上的抱怨只是冰山一角。I suspect they were right。我感觉他们是对的。
3、doubt举例：Others doubted whether that would happen。其他人认为那未必会发生。his raises doubts about the point of advertising这对做广告的意义提出了疑问
