The menus are in the language you selected, but the characters still speak another language. That may be a supported combination rather than a broken installation. Interface text, subtitles and full audio are separate kinds of language support.
Read the game’s language table
Check the official store listing for the edition and platform you are using. A tick beside interface support does not automatically mean recorded dialogue exists in that language. Likewise, subtitles may be available even when the spoken performance remains unchanged.
Steam’s language-settings guidance notes that language files may need downloading and directs players to the game’s supported-language information. Other launchers and consoles have their own arrangements, so use the documentation for the actual version.
Check the download before going offline
If the game requires an optional audio pack, install it while you have a suitable connection and sufficient storage. Let the download complete, then open a section containing dialogue to confirm the result. Seeing the right language in the main menu is not a complete test.
Look for separate in-game controls for spoken audio and text where available. Some games allow mixed settings; others tie them together. Record the original choice before changing it, especially if you are navigating menus in a language you do not read comfortably.
If a promised language is missing, collect the edition, platform, region where relevant and installed version before contacting official support. Do not assume that a language pack offered for another edition or platform will work with yours.
Unverified replacement files can introduce compatibility or security problems. Prefer supported options and explain the limitation clearly when helping another player. A useful recommendation says “this edition has English menus and subtitles, but not English spoken dialogue,” rather than the ambiguous claim that the game “supports English.”