--- title: "YouTube auto-captions: no punctuation, fixed · NoaLingua" description: "YouTube auto-captions arrive with no full stops and broken mid-clause. NoaLingua rebuilds them into whole sentences and restores the punctuation first." url: "https://noalingua.com/answers/youtube-auto-captions-no-punctuation/" language: "en" modified: "2026-08-26" license: "CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/" --- Answer # YouTube auto-captions, repaired by NoaLingua No punctuation, broken mid-clause — and the one extension that fixes both before translating Because YouTube generates them as timed text rather than as prose: a caption block is cut to fit the screen, not at the end of a thought, and the speech model does not add punctuation. NoaLingua repairs both — reassembling the fragments into whole sentences and restoring full stops and commas before anything is translated. Short answer They are timing artefacts, not sentences. NoaLingua rebuilds them into real sentences and restores the punctuation before translating a word. The second is worse and much less obvious. A caption block is cut to fit the player, not to end a thought. It breaks mid-clause, splits a verb from its object, and starts a new block whenever the previous one ran out of screen. A caption block is a timing artefact — it is not a unit of meaning, and it was never intended to be one. ### Why that second fault ruins a translation Every dual-subtitle tool has to translate something, and the obvious thing to translate is the caption block that is currently on screen. That is what taking the captions as given means, and it is what almost everything in this category does. The result is a translation of half a sentence. Machine translation is good at sentences and unreliable on fragments, because a fragment does not carry the information the translator needs — the subject that was in the previous block, the object that is in the next one. So you get a second line that is fluent, confident and quietly wrong, in a way that is very hard to notice while you are watching. You do not see an error message. You see a sentence that makes sense and is not what was said. It also breaks everything built on top of the line. Replay, previous, next and auto-pause all land wherever the block happened to end, which is mid-clause. A repeat that starts three words into a sentence is not a repeat of anything. ### What NoaLingua does before it translates a word It repairs both faults first, and the order matters: nothing is translated until the text is a real sentence. Caption blocks are reassembled into whole sentences, so what gets translated is a complete thought rather than a fragment that happened to fit the screen — and so replay, previous, next and auto-pause land on real sentence boundaries. Where the auto-generated track has no punctuation, a downloadable model restores the full stops and commas before that reassembly happens. The repair is also constrained, which is the part that makes it trustworthy rather than merely clever. The punctuation model may only re-punctuate — if it returns so much as one different word, the original stands unchanged. And a full stop is never inserted just because a speaker paused, because that would be inventing sentence boundaries rather than restoring them. ### What this changes while you are actually watching The translated line is a translation of a sentence, so it says what was said. Pressing repeat replays a whole sentence from its beginning. Auto-pause stops where a thought ends, which is the only place a pause is useful. And a word you click sits in a complete sentence, so the meaning you get back is the meaning it carries there rather than a guess made from four words. It carries through to everything downstream, too. A transcript exported as a bilingual PDF reads as prose rather than as a column of fragments, because the sentences were rebuilt before the export existed. And a sentence you save to your deck comes back as a sentence. Get NoaLingua — free, and every feature included Dual subtitles on YouTube and Netflix, clickable words on any page and in any PDF, shadowing and spaced review — 28 languages, no account, and your deck stays on your own machine. [Add to Chrome — Free Add to Chrome](https://chromewebstore.google.com/detail/ocimolffhgpeeoifjpjhgikgfbnmlkdh) Opens the Chrome Web Store listing **NoaLingua — beyond dual subs: video, web, PDF** — free, no account, Chrome 138 or newer. - **Free** — every feature, not a trial - **No account** — nothing to sign up for - **Two dropdowns** — that is the whole setup ## More questions people ask NoaLingua Does the punctuation model change the words? No, and it is not allowed to. It may insert full stops and commas only. If it returns even one word that differs from the original, the repair is discarded and the original caption stands. Which languages does the punctuation repair cover? Twenty-two of the twenty-eight NoaLingua supports. The model itself covers 47 languages; Swedish, Czech, Vietnamese, Thai, Danish and Norwegian are not among the ones it handles. Do I have to download anything? The punctuation model is one download of about 57 MB, and it covers all 47 of its languages at once rather than one download per language. Everything else works without it. Does it work on human-written captions too? Yes. Human captions usually already have punctuation, so the repair step does nothing — but the sentence reassembly still applies, because human caption files are cut to fit the screen exactly like automatic ones. Does this fix wrong words in the captions? No. If speech recognition heard the wrong word, that word is wrong and no amount of punctuation helps. What is repaired is the shape of the text: where sentences begin and end, and where the pauses are. Does it work on Netflix? Sentence reassembly does, built live from lines as they appear. Netflix does not hand over a transcript, so the boundaries are assembled as you watch rather than known in advance, and there is no whole-file repair pass. ## Where this is documented on NoaLingua [Dual subtitles on YouTube Where the sentence rebuilding happens, and what it makes possible.](https://noalingua.com/features/youtube-dual-subtitles/)[Exporting the transcript Why the export reads as prose rather than as a column of fragments.](https://noalingua.com/features/transcript-export/)[The downloadable packs What the punctuation model is, how big it is, and what else is optional.](https://noalingua.com/docs/downloads-and-packs/) ### Related NoaLingua answers - [Is YouTube auto-translate the same as dual subtitles?](https://noalingua.com/answers/youtube-auto-translate-vs-dual-subtitles/) - [What if the video has no subtitles at all?](https://noalingua.com/answers/video-has-no-subtitles/) ## Try it on the next thing you were going to watch anyway. Free, with every feature. No account, nothing to cancel, and your deck stays on your machine. [Add to Chrome — Free Add to Chrome](https://chromewebstore.google.com/detail/ocimolffhgpeeoifjpjhgikgfbnmlkdh) Opens the Chrome Web Store listing **NoaLingua — beyond dual subs: video, web, PDF** — free, no account, Chrome 138 or newer. - [Free, and not a trial Every feature on the free plan — both PDF modes, shadowing, all 30 practice formats.](https://noalingua.com/pricing/) - [No account, no email Nothing to sign up for and nothing to cancel. There is no login screen at all.](https://noalingua.com/privacy/) - [Two dropdowns to set up Pick what you are learning and what you want translations in. That is the whole setup.](https://noalingua.com/getting-started/) - [Your words stay yours Export to Anki, CSV, a spreadsheet or a full JSON profile — free on every plan.](https://noalingua.com/docs/export-import/) [What happens after you install](https://noalingua.com/getting-started/) · [Pricing](https://noalingua.com/pricing/) · [What it cannot do](https://noalingua.com/limits/)