Language Learning Research from Real YouTube Videos
Numbers measured from 2,518 Japanese and 2,146 English YouTube videos with word-level aligned subtitles. Every report explains its method and comes with free CSV data under CC BY 4.0.
- How Fast Do People Speak on YouTube? Japanese and English Speaking Speed by LevelJapanese YouTube videos are spoken at a median 6.3 morae per second and English videos at 183 words per minute. Beginner Japanese (JLPT N5) videos run 36% slower than N1 videos.
- How Many Words Do You Need to Follow YouTube Videos? Coverage by JLPT and CEFR LevelRecognizing 95% of the words in English YouTube videos takes the 3,814 most frequent words; in Japanese videos it takes 8,651. The top 1,000 words alone cover 86% of English and 78% of Japanese.
- Gonna, Gotta, You Know: How Often Reduced Forms and Fillers Appear in Real English Videos“Gonna” appears 13.1 times per 10,000 words of English YouTube speech and shows up in 28% of videos, about 14 times as often as “wanna”. The filler “you know” is even more frequent, at 14.6 per 10,000 words.