tom have made some mistake in his test这句话语法有错误么?
1.为什么不是tom have made some mistake in his test 而是tommade some mistake in his test 呢?
2.还有现在完成时的疑问句和过去时的疑问句有什么区别.比如Have you seen my food ?和Did you see my food?有什么不同?