The Grammaring Guide to English Grammar with Exercises

Subject-auxiliary inversion with SO and NEITHER / NOR to express agreement

So + auxiliary + subject is added to a positive statement to express agreement, and neither/nor + auxiliary + subject is added to a negative statement for the same purpose:

I suggested that he should take the job, and

so did all his friends

.

(his friends also suggested that he should take the job)

Everybody knows that, and

so should you

.

(you should know that, too)

"I love South Korean films." "Really?

So do I

."

(I also love South Korean films)

"I am not going to Andy's party tonight." "

Neither/nor is Susan

."

(Susan isn't going either)

"My family have never been on a holiday abroad." "

Neither/nor have mine

."

(my family haven't been either)

If we want to express disagreement, there is no inversion:

"I love South Korean films." "

I don't

."

"I am not going to Andy's party tonight." "

Susan is

."