一般现在时：指平常时有发生的事情,如：He loves to run.
现在进行时：指当前正在发生的事情,如：He is now running.
一般过去时：指发生在过去的事情, 如：he ran yesterday.
过去进行时：指过去某个时间点正在发生的事情,如：he was running yesterday when I was standing alone.
一般将来时：指按计划会在不久将来发生的事情,如：I will go to school tomorrow.
现在完成时：指对于当前已经完成的事情,强调其结果：I have been here for a long time.
过去完成时：指对于过去某个时间点而言已经完成的事情,强调其结果对过去某个时间点的影响：I had been here for a long time before you arrived.