English-language skills are a near necessity in today’s global economy. While prior studies of language acquisition have focused on schools, we show the overwhelming influence of out-of-school learning stemming from historically rooted differences in whether countries subtitle or dub foreign TV content. We identify the causal effect of subtitling in a cross-country between-subject approach that compares English to math skills in European countries that do and do not use subtitles. We find a large positive effect of subtitling on English-language skills of over one standard deviation. Consistent with oral TV transmission, the effect is larger for listening and speaking skills than for reading. Placebo tests do not show effects on native-language reading or science skills. Results are robust to accounting for linguistic similarity, economic incentives to learn English, and cultural protectiveness.