英语共有十六种时态，其表现形式如下（以study为例）
一般时 进行时 完成时 完成进行时
现在 study be studying have studied have been studying
过去 studied be studying had studied had been studying
将来 will study wil be studying will have studied will have been studying
过去将来would study would be studying would have studied would have been studying
时态（Tense）是表示行为、动作和状态在各种时间条件下的动词形式。因此，当我们说时态结构的时候，指的是相应时态下的动词形式。
