Does it matter whether I watch with subtitles in English or in Persian?

Yes, based on the general research: same-language text (captions in the language you're learning) tends to help vocabulary and listening more than subtitles translated into your native language. One study found that watching with subtitles in the learner's own language actually blocked the small listening improvement that watching without any subtitles produced. So if you can find Persian-language captions for Persian content, they are likely more useful than English subtitles, though no study tested this with Persian specifically.

How many hours of watching would I realistically need to see progress?

The sources don't give a firm number, but the scale involved in the clearest success story was large — roughly 2,500 TV episodes and 16 movies over time — and vocabulary gains from a single episode or short viewing session tend to be small, often just a handful of words. This suggests progress from viewing alone builds slowly and works best as a long-term, cumulative habit rather than something that pays off after a few sessions.

Should I watch movies or TV series if I want to learn Persian through video?

The evidence favors series over one-off movies for word learning, because a single ongoing show lets you encounter the same vocabulary, characters, and phrases repeatedly, which several studies link to better retention than more varied, one-time content.

Will watching Persian movies help me learn to speak or write Persian, not just understand it?

The sources mostly measured listening comprehension and vocabulary recognition, not speaking or writing ability, so there is little direct evidence here that movie-watching alone builds those productive skills. If speaking and writing are your goals, the research points toward supplementing viewing with practice activities like conversation or writing exercises.

Can I learn Persian just by watching movies?

Evidence-based answer · Last updated 24 Aug 2026 · How it’s made

The short answer

No — the research says watching movies alone won't get you to fluency in Persian or any language, but it can meaningfully boost vocabulary and listening skills as a supplement, especially once you already have some base knowledge. None of the sources studied Persian specifically, so this answer relies on general second-language research (mostly English-learning contexts); nothing here suggests Persian's writing system or grammar would change the picture in a special way.

Asked as someone learning Persian (beta). Findings drawn from Persian-specific research are framed for Persian learners and may not hold for other languages; where the evidence is general second-language research, the report says so.

Persian has a thinner research base than our core languages, so this answer may lean on general second-language findings.

Vocabulary gains from watching are real but modest

Across many studies, learners do pick up new vocabulary just from watching TV shows or movies without any studying, but the amount is small — a large meta-analysis found viewing conditions produced the lowest incidental vocabulary gains (about 5-7%) compared to reading or listening alone (13-18%).^3,6,7

In plain terms

"Incidental" learning means picking up words as a side effect of watching for enjoyment or meaning, not because you're deliberately trying to memorize them.

One learner's extreme case isn't the norm

The most dramatic success story in this evidence — a learner who reached strong English proficiency after watching roughly 2,500 TV episodes and 16 movies — represents thousands of hours of exposure over a long period, not a quick shortcut, and even then it mainly built listening skill and vocabulary rather than full, well-rounded fluency.¹

Captions and subtitles change the outcome a lot

Whether and how text appears on screen strongly affects how much you learn: same-language captions (text in the language you're learning) tend to help vocabulary and listening more than subtitles in your native language, and no text at all can also produce a smaller but real listening improvement.^8,10,11,12

Example

For an English speaker learning Persian, this would mean watching a Persian film with Persian captions turned on (if available) rather than English subtitles, since matching the on-screen text to the spoken language reinforces the sounds and words you're trying to learn.

Your existing level determines how much you get out of it

Learners who already had higher proficiency and stronger vocabulary before they started watching gained more from viewing than beginners did, and comprehension improves the more content a viewer already understands.^2,3,13

Repeated, similar content beats one-off viewing

Watching many episodes of the same show, or content with recurring characters and vocabulary, produces bigger gains than watching a single unrelated movie, likely because words and phrases repeat and get reinforced.^1,14,15

Example

Watching one whole season of a single series works better for learning than watching several unrelated films, because you keep re-encountering the same words, character names, and phrases in context.

Movies build some skills far more than others

Movie/TV watching mainly strengthens listening comprehension and vocabulary recognition; the sources reviewed show comparatively little evidence that watching alone develops speaking ability, grammar accuracy, or writing.^1,4,9

Structured or supplemented viewing outperforms passive watching

Studies that added pre-teaching of key words, guided activities before or after viewing, or comprehension checks produced better vocabulary results than just watching passively; one classroom study found the group that watched with structured activities gained far more than a textbook-only control group.^2,4,5

What to do with this

Treat movies and TV as a strong supplement, not a stand-alone method, for learning Persian.
Since the underlying research isn't Persian-specific, the safest approach is to apply what works in general second-language studies: build at least a basic vocabulary and grasp of Persian sounds/script first (through a course, tutor, or structured resource), because viewing helps more once you're not totally lost.
Favor extensive viewing of one show over many hours rather than scattered single movies, so vocabulary and phrases repeat enough to stick.
Turn on Persian-language captions if you can find them, rather than English subtitles, since matching text to spoken audio reinforces the target language more than translation does; if Persian captions aren't available, watching with no subtitles at all still beats relying on English subtitles.
Pair viewing with active habits — looking up new words, replaying tricky lines, or discussing what you watched — since studies that added this kind of structure saw bigger gains than passive watching alone.
Finally, plan on using separate practice (speaking with people, writing, structured grammar study) for skills like speaking and grammar, which the evidence suggests movies don't develop much on their own.

Now pick something to do it with

Each of these opens an overview of the apps, courses and immersion material worth a look for that — filtered to exactly what the advice above points you at:

Immersion / input Listening practice Resource selection Sentence mining

Or see the full resource list

Worth knowing

None of the studies cited involve Persian learners or Persian-language media; all of the evidence comes from research on English or other European/Asian language learners, so any application to Persian specifically is an extrapolation, not a direct finding.
Persian uses a different script (Perso-Arabic) and has different sounds and grammar from English, and the sources say nothing about whether these particular features change how well movie-watching works — this report cannot speak to that directly.
Reported vocabulary gains also vary widely between studies (from single digits to 30%), reflecting real differences in learner level, material difficulty, and how "learning" was measured, so exact numbers shouldn't be treated as fixed expectations.

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[1]Lanoke Intan Paradita, Haira Rizka, Banatul Murtafi’ah, L. Mauludin, Gatot Prasetyo. ‘I can now hear the pauses’: the narratives of L2 listening and vocabulary development through extensive viewing. Cogent Arts & Humanities 2025. doi.org/10.1080/23311983.2024.2448904
[2]Geòrgia Pujadas, Carmen Muñoz. Extensive viewing of captioned and subtitled TV series: a study of L2 vocabulary learning by adolescents. Language Learning Journal 2019. doi.org/10.1080/09571736.2019.1616806
[3]Michael Rodgers. English language learning through viewing television: An investigation of comprehension, incidental vocabulary acquisition, lexical coverage, attitudes, and captions. 2013. doi.org/10.26686/wgtn.17005078
[4]Javid Babayev. Impact of Movies in Second Language Learning. Porta Universorum 2026. doi.org/10.69760/portuni.26030004
[5]Safnidar Siahaan, R. W. Eriyanti, A. Rofieq, Atok Miftahul Huda. Students' perception regarding the integration of English-subtitled films in language learning. CAHAYA PENDIDIKAN 2024. doi.org/10.33373/chypend.v10i1.5948
[6]E. Peters, S. Webb. INCIDENTAL VOCABULARY ACQUISITION THROUGH VIEWING L2 TELEVISION AND FACTORS THAT AFFECT LEARNING. Studies in Second Language Acquisition 2018. doi.org/10.1017/S0272263117000407
[7]Stuart Webb, Takumi Uchihara, Akifumi Yanagisawa. How effective is second language incidental vocabulary learning? A meta-analysis. Language Teaching 2023. doi.org/10.1017/s0261444822000507
[8]J. Birulés-Muntané, S. Soto-Faraco. Watching Subtitled Films Can Help Learning Foreign Languages. PLoS ONE 2016. doi.org/10.1371/journal.pone.0158409
[9]Dru Sutton, Stuart Webb. The effects of audiovisual input on second language learning: A meta-analysis. Studies in Second Language Acquisition 2026. doi.org/10.1017/s0272263126101612
[10]Bellalem, Fouzi, Neddar, Bel Abbes, Bouagada, Habib, Djelloul, Dalila Benelhadj. The Use of Subtitled Movies for Vocabulary Acquisition in ESP Settings: Insights from an Experimental Study in Algeria. Arab World English Journal 2018. https://eric.ed.gov/?id=EJ1313407
[11]Hossein Sabouri, Simin Zeynali, Parya Tadayyon. Subtitled Adventures: The Impact of Subtitles on EFL Students' Vocabulary and Listening Skills While Watching Toy Story 4. International Journal on Studies in English Language and Literature 2025. doi.org/10.20431/2347-3134.1310001
[12]Rong Wei, Lin Fan. On-Screen Texts in Audiovisual Input for L2 Vocabulary Learning: A Review. Frontiers in Psychology 2022. doi.org/10.3389/fpsyg.2022.904523
[13]Rongrong Zhuo, Yuqing Wang. A Study of Impacts of Audiovisual Input Modes on Incidental Vocabulary Acquisition in Second Language Learning. Scientific Journal Of Humanities and Social Sciences 2025. doi.org/10.54691/kgkkes42
[14]Anastasiia Pattemore, Vincent Fan, Laura Fiche, H. Loerts. Investigating the effects of prolonged exposure to textual enhancement on attention and learning: a pre-posttest measures eye-tracking study. Applied Psycholinguistics 2025. doi.org/10.1017/S0142716425100258
[15]Duy Van Vu, A. Noreillie, E. Peters. Incidental collocation learning from reading-while-listening and captioned TV viewing and predictors of learning gains. Language Teaching Research 2023. doi.org/10.1177/13621688221151048