In Present perfect^x, Plurals^x, Grammar^x

WANG CHUN wrote: 1. Ancient and modern human beings use their great intelligence to invent machines that help people lead a comfortable and convenient life. My problem with this sentence is that it is not possible for ancient human beings to do anything any more, so using the present tense...

Susan, I understand the frustration you are feeling. Your language, Chinese, is what linguists call an "isolating language". All information, such as the time an action occurred, is conveyed by the choice and order of words in a sentence. There are no verb tenses. There are no plurals. In fact,...