Hello, Grammar Exchange members!
The following sentence is found in a PDF file from the Internet. (The address of the web page is https://jimwood8.files.wordpre...inversion-nov-22.pdf)
1. Just as some children ignore their parents, so too do some parents ignore their children.
The first question I'd like to ask is whether or not the inversion in the main clause in (1) is optional.
I have one more sentence that makes me wonder. (source: Adaptive Education: An Inquiry-Based Institution by Robert VanWynsberghe, Andrew C. Herman, p.23)
2. Just as other living creatures thrive or perish depending on how well they adapt to the environment, so too do humans, although the consequences are not usually so dramatic.
In this case, I think the inversion in the main clause in (2) cannot be optional. Because if my friend says "I like baseball," I can say to that "So do I." As far as I know, "I do so" is not grammatical.
I'd like to hear your opinions.
Thanks in advance.