Occasionally I see constructs like this in English sentences:


  
  Not only is this true in this case, but ...
  


What puzzles me is the "is this" part of it. The sentence is not a question, yet it seems to have a question-like order. Isn't this correct/preferred:


  
  Not only this is true in this case, but ...
  


Are there other cases where non-question sentences contain question-like parts (so to speak)?


Question: Will installing Ubuntu using Wubi erase Windows?
Answer: No, wubi runs under windows. So it won't remove the host OS. 

It is like running virtual system. 

Know more - https://wiki.ubuntu.com/WubiGuide