The theme can speak to visitors in Czech or English. Czech is the default and the switch is a single key in _config.yml.
Obsah
Switching
lang_ui: en # or cs
The value has to match a file name in _data/lang. Nothing else needs changing; the whole interface follows once the site is rebuilt.
What it covers
Everything the site author did not write. Navigation items, buttons, the strings around posts, the search dialog, share button labels, the footer and the 404 page.
Two less obvious things change with them. The lang attribute in the document head, which is how browsers and screen readers know what language the page is in. And the date format, because Czech writes 17. 7. 2026 where English writes Jul 17, 2026.
Where the strings live
In two files, _data/lang/cs.yml and _data/lang/en.yml. Both carry the same set of keys:
html_lang: "en"
date_format: "%b %-d, %Y"
read_more: "Read more"
written_by: "Written by"
share: "Share"
The keys are named in English on purpose. Anyone who needs to find their way around the theme can tell what read_more or written_by does without speaking Czech.
Plural forms
Czech needs three forms where English needs two. That is why post counts and reading time come as a set of three keys:
count_one: "1 post"
count_few: "posts"
count_many: "posts"
In English the last two values are identical, which is perfectly fine.
A third language
Copy en.yml under a new name, say de.yml, translate the values and set lang_ui: de in the configuration. Leave the keys alone - the templates refer to them.
Two things to watch
The language files do not cover everything.
Page content. The text on the About, Contact and Privacy pages is content, not interface. The site author writes it and translates it by hand.
Titles of the built-in pages. The title and description values sit in front matter, where Liquid is not evaluated, so a language file cannot reach them. Switching the site to English means editing five lines by hand, plus the page file names and their permalink values so the URLs match the language of the site.
It is a few minutes of work, but it does have to be done.
