The man sitting by the window is our teacher.要改过去时怎么改啊

这个句子中,动词是is.
要改成过去时,先改动词,之后再对句子中其他成分做相应的改动就可以.
要改成过去时,先得把is改成was,sitting by the window不用改.
所以改了之后是：
The man sitting by the window was out teacher.
再问： The man who is sitting by the window is our teacher。从句的话 who is sitting by 用改么 另外 He is a teacher, suvived in earthquake。 用suvived 还是 suviving 主动还是被动呢· 后半句有无时态变化 谢谢你
再答： 需要改，因为这里从句中也有个动词is，也得改成was。 所以改了之后是： The man who was sitting by the window was out teacher.
再问： 明白了 He is a teacher, suvived in earthqu 但是用suvived 还是 suviving 主动还是被动呢· 后半句有无时态变化 这是关键如果改成从句He is ateacher , who suvived in earthquake。后半句也要改失态吧 谢谢了 最后一个问题
再答： 用survived表示过去时，不是主动或者被动。 后半句的确得改时态，因为在地震中存活是过去的动作。