In IMDB
The Secret of Marrowbone (2017)
Marrowbone (original title)

Also Known As (AKA)
(original title) - Marrowbone
World-wide (English title) (literal title) - The Secret of Marrowbone

I was under the impression the display title here was the earliest English-language general release title. Marrowbone was the festival title. Spanish release title was El Secreto del Marrowbone and the UK release title is The Secret of Marrowbone.

When you say Here, what country are you talking about?

I'm talking about the English-language TMDB. General release titles supercede festival premiere titles, no?

I went to read the Bible.
https://www.themoviedb.org/bible/movie#59f3b1749251414f2000000c
English is not my language.
What I understand is: The title in English will be the one used by the first English-speaking country to display the film.
That was more or less my memory.
That's why I asked you, what country are you talking about.
Looks like Canada showed up first at a festival.
Anyway, I'd rather have a more experienced Moderator give us an opinion.

Edit
Country: Spain
Language: English
https://www.imdb.com/title/tt5886440/

Sorry, I didn't realise it was released already in the US in April as Marrowbone. My mistake.

The correct original title is the Spanish one. We don't take in account the festival releases. (Maybe the rules were different in 2018 as the writing of the Contribution Bible has started in 2017-2018).

It is is mainly produced by Spanish companies. So, the origin language should be Spanish.

The language listed on IMDB is the spoken language, which is correctly set to English.