"He added" vs. "Did he add" (inversion after negative adverb) [duplicate]

I'm reading a book, and I found a sentence where I don't understand the grammar. It seems as the writer wants to write a statement, but uses the structure of a question. The sentence is highlighted in the following paragraph:

In the first ten paragraphs, he touted his engineering skills, including his ability to design bridges, waterways, cannons, armored vehicles, and public buildings. Only in the eleventh paragraph, at the end, did he add that he was also an artist. "Likewise in painting, I can do everything possible," he wrote.

Isaacson, Walter. (2017) Leonardo da Vinci.

Shouldn't that sentence start with "he added" instead of "did he add" since it's not a question? If it's correct, is it something people usually use when they speak, or is it more like something you would find in books?

Solution 1:

In older Modern English, it was not uncommon for a sentence that was fronted by an adverb to have the subject and verb inverted:

I love her dearly." - "Dearly do I love her.

"They fought long." - "Long did they fight."

This is now retained chiefly in literary use and in certain contexts:

Random Idea English at http://random-idea-english.blogspot.com/2014/09/exploring-inversion-and-fronting.html has a good explanation

Inversion and fronting Inversion is often used in connection with fronting. Sometimes fronting involves inversion, often it doesn't. Sometimes that inversion is obligatory, sometimes it isn't.

• Fronting of a negative adverb, with obligatory inversion.

He had never seen such a wonderful sunset. (standard word order)

Never had he seen such a wonderful sunset. (fronted with inversion)

• Fronting of a prepositional phrase, with optional inversion

A large dog lay in front of the fireplace. (standard word order)

In front of the fireplace, lay a large dog. (fronted with inversion)

In front of the fireplace, a large dog was chewing a bone. (fronted, no inversion)

• Fronting of wh-clause - here inversion is not possible

I've no idea why she's late. (standard word order)

Why she's late, I've no idea. (fronted, no inversion)

The commonest uses are “so do I” and “neither do I”