Primary language – Failed

Primary language – Failed is a result from the Accessibility Checker in Adobe Acrobat Pro, in its Document category. It means the PDF doesn't say what language it's written in. Adobe's help explains that setting the document language lets some screen readers switch to the right language. Without it, a screen reader guesses, and a Spanish notice may be read aloud with English pronunciation.

What this means

A PDF stores its language as a short code, such as en-US for US English or es for Spanish. There's one main language for the whole document, and any passage in another language can carry its own code on its tag in the document's hidden structure. Three different things can go wrong:

• Missing: the document has no main language at all. This is what Acrobat's rule checks.
• Invalid: the code isn't a real language code. "English" isn't valid, and neither is en_US, because language codes use a hyphen, not an underscore. Assistive technology ignores invalid codes, so they're no better than none.
• Unmarked passages: a Spanish paragraph in an English document isn't marked as Spanish. Acrobat doesn't check this one, but WCAG does.

That last point matters for many public agencies, whose notices often include English and Spanish side by side. Each version needs its own language, or one of them will be mispronounced.

Why it matters

Screen readers use the language setting to pick a voice and pronunciation rules. With the wrong language, words are mangled, sometimes to the point of being unintelligible. Braille displays can also use the wrong translation rules. This affects screen reader and braille display users, and it's covered by WCAG 2.1 success criteria 3.1.1 Language of Page and 3.1.2 Language of Parts.

How to fix it in Acrobat Pro

Fix it in the source file

Language set in the source carries into the PDF:

• Word: select the whole document and choose Review > Language > Set Proofing Language to set the main language. For a passage in another language, select it and set its proofing language separately. Microsoft documents that recent versions of Word mark text in a different language with its own language code when exporting to PDF.
• PowerPoint: use Review > Language > Set Proofing Language in the same way.
• InDesign: set the language in your paragraph and character styles, and set the document language under Advanced > Accessibility Options when you export.

For bilingual documents, consider separate English and Spanish versions. They're easier to read aloud, and easier to keep up to date.

Fix it automatically with Includoc

Includoc fixes the main language automatically. We detect the document's language, set it for the whole document, and replace any invalid language codes with the detected language.

Passages in another language are assisted. We detect language changes, such as a Spanish paragraph in an English notice, and mark them with their own language. You confirm those passages on the review screen, because short phrases, names and place names are easy for any detector to misjudge.

Standards

Related errors

• Title – Failed: the other document-level setting that screen readers announce first.
• Bookmarks – Failed: another document-level check in the same Acrobat category.

For the full checklist, read How to make a PDF accessible, or check a PDF free to see the language your file declares.