一般过去时,如果是主谓宾结构,直接将谓语动词变成过去时. 如:He comes into the room.-> He came into the room. 如果是主系表结构,就将系动词be改成过去时 was/were. 如:He is young.-> He was young. 如果句子中有be+动词(过去分词)的用法,一般是被动语态. 如:He is made to do the work by his boss.他的老板让他做这项工作(他被他的老板叫去做这项工作) 如果句子中有be+动词(现在进行时),则是现在进行时态. 如:He is working on the project.他正在做这个工程.