Original language is not the track list
A title page's original-language field describes the production. The viewing edition determines which subtitles, captions and dubbed audio tracks are offered. Open that service's language menu before assuming a catalogue label promises your preferred combination.
Subtitles primarily carry dialogue. Captions may also describe sounds or identify speakers. Dubbed audio is a different spoken performance. Choose what suits the people watching rather than treating one option as the only correct way to see the film.
Make text readable from your seat
Where customization is available, adjust size, outline or background. Test a bright scene as well as a dark one. Large text that covers action is not necessarily more comfortable than slightly smaller text with a clear outline.
When timing is wrong
Pause and resume, or switch to another supplied track. Use a timing adjustment only if the player offers one. Changing the film's speed repeatedly is not a reliable repair for a mismatched subtitle file.
If dialogue is hard to hear, captions can help even in your own language. Also check the device's dialogue or night mode, if present. Picture quality and language controls are separate settings, so change the one related to the problem.