What's wrong
Omitting the `lang` attribute causes assistive technology to default to the user's system language, mispronouncing words.
Who it affects
Screen reader users hear English text spoken using French or German phonetic engines, making text unintelligible.
How to fix on WordPress
In `header.php`, output `<html <?php language_attributes(); ?>>`.
Code example
Problematic Code
PHP
<!DOCTYPE html>
<html>Recommended Accessible Code
PHP
<!DOCTYPE html>
<html <?php language_attributes(); ?>>How to check your fix
Inspect the root element in DevTools Elements panel. Verify `<html lang="en">` (or matching store locale) is present.