Although Class Central lists online courses in 87 languages, courses made in English outnumber all of the others by more than six to one. English is therefore a useful language to know, even though some courses have subtitles in a range of languages. Earlier this year, we updated our list of courses to help improve your writing skills. These courses all assume some fluency in the language. But what if you do not know any English, or your English is very poor? If you do not have convenient acce

Unlike multiple-choice questions, peer-reviewed assessments are manually graded by other learners.

TL;DR Duolingo reported Q4 2025 revenue of $282.9 million (+35% YoY), closing its first billion-dollar year, breaking estimates again. The stock dropped 22.5% anyway. Again. The company plans to slow down monetization to grow to 100 million DAUs until 2028, by focusing on teaching quality, giving more to free users, and growing non-language courses. Duolingo’s Q4 2025 results confirmed something we highlighted in its 2025 review: growth is slowing. The company crossed a billion dollars in r