Choose the version before the opening scene
On the viewing page, look for the audio and subtitle controls. A production's original language is not a list of every available track. The same film may offer different dubs or captions on different services or in different countries.
Subtitles, captions and dubbed dialogue
A translated subtitle follows the meaning of the original performance. A dub adapts spoken dialogue for another language and may use different wording. Captions can also describe sounds or identify speakers. Pick the specific option you need rather than assuming every text track contains the same information.
When the words are difficult to read
If the player allows it, adjust the size, outline or background. Bright animation may benefit from a subtle dark backing; a small phone screen may need a larger font. Check a dialogue scene after changing the setting rather than judging it from the menu alone.
When timing slips
A fixed delay can sometimes be corrected with a timing control. An increasing mismatch may indicate a different cut or frame rate. Try another listed track or edition before continuing to adjust the same offset. For anime, confirm that the text track corresponds to the audio version you chose.