Reading the documentation at https://quarto.org/docs/authoring/language.html I get the impression that defining `lang: fr` in the metadata (_quarto.yml) of a project will allow the translations for French to be done for things like "Table des matières" instead of "Table of contents". In fact, this doesn't work in my project, neither for PDF nor HTML output. I tried putting `lang: fr` in the `project:` part of the metadata and also the `book:` part. 

In the output of the `quarto preview . --render all` command, there is no information showing the language settings, so perhaps it's not being passed to pandoc, etc. I know pandoc supports this feature, because I have used it on other projects before coming to quarto.

The workaround for me is to put `language: _language.yml` in the `project:` part (I copied _language.yml from [quarto-cli](https://github.com/quarto-dev/quarto-cli)/[src](https://github.com/quarto-dev/quarto-cli/tree/main/src)/[resources](https://github.com/quarto-dev/quarto-cli/tree/main/src/resources)/[language](https://github.com/quarto-dev/quarto-cli/tree/main/src/resources/language)/_language-fr.yml)
2022-05-15T14:16:26Z
fuhrmanator
closed
Can't get "lang: fr" to work in _quarto.yml (Book)
https://github.com/quarto-dev/quarto-cli/issues/882