一般过去时 She was very tired when she got home(当她回家的时候,她感到很疲倦) 一般现在时 John tells me you will leave tomorrow(约翰告诉我你明天就要离开了) 现在进行时 These days we are helping the farmers work on the farm.(这些天我们正在农场帮助农民工作) 现在完成时 I have heard nothing from him up to now.(到目前为止我没有他的任何消息.) 过去完成时 I had been at the bus stop for 20 minutes when a bus finally came.(当车来的时候,我在车站已等了20分钟.)