什么情况下用so it is with

当前面既有肯定又有否定
或两个谓语时用so it is/was with
也可以用so it is the same with
He likes apples and he doesn't go to school by bus.
So it is with her
而so do I 这一类是前面是肯定的情况也适用于另一主语
They go to school by bus.
So do we.

1.如果前面的两个以上的句子的动作或状态，后面的人也如此，要用so it is/was with sb.
如:He is a boy and he likes singing. So it is with Tom.
2. so + be/do +sb./sth.用于一个句子，并且前后两个句子的主语是两个的时候。如：Tom is a boy, so is Bob.
Tom likes singing, so does Bob.

因为前面这句mr cheng is an engineer and works very hard.里又有BE动词又有一般现在时态，用SO DOES HIS WIFE 和 SO IS HIS WIFE显然都不确切，所以只好用SO IT IS WITH HIS WIFE。如果就光是MR。CHENG IS AN ENGINNER，可以用SO IS HIS WIFE。如果只是MR。CHENG WORKS VERY HARD，可以用SO DOES HIS WIFE。

当前面既有肯定又有否定,或两个谓语时