Can you learn a language in 15 minutes a day?

How far does 15 minutes a day get you?

Fifteen minutes, every day of the year, is 5,475 minutes: a little over 91 hours. Set that against the most widely quoted estimates of how long a language takes and the picture is honest rather than glamorous.

Cambridge calls its figures a guideline only. They describe lessons and supervised study for learners of English, and they shift with your background, how intensively you study, your age and how much contact you have with the language outside lessons. The US Foreign Service Institute, which trains diplomats towards professional working proficiency, budgets 24–30 weeks and 552–690 class hours for languages close to English such as Spanish, French, Italian, Portuguese, Dutch and the Scandinavian languages, with 17 hours of self-study a week on top. German sits at about 36 weeks, and Japanese, Korean and Mandarin at 88 weeks and 2,200 class hours.

Apps are no exception. In a study of 225 adults who finished the early units of Duolingo's Spanish or French courses, learners had spent a median of 112 hours on the app and reached Intermediate Low in reading, comparable to university students after four semesters. The authors include Duolingo employees, and time on the app showed only very small, non-significant correlations with test scores: hours matter, but not every hour is equal.

Is a little every day better than one long session?

For remembering vocabulary, the evidence leans clearly towards spreading practice out. In a 1981 study by Bloom and Shuell, high-school students of French learned 20 words either in three 10-minute sessions on three successive days or in one 30-minute session. Straight afterwards the two groups scored almost the same (16.85 and 16.12 words). On a retest several days later, the spaced group recalled 15.04 words and the crammed group 11.15, about 35% more.

A 2022 meta-analysis by Kim and Webb pooled 48 second-language experiments with 3,411 participants and found that spacing had a medium-to-large effect on learning. Longer gaps between sessions did no better than shorter ones on immediate tests but did better on delayed ones.

Whole courses are a different question, and here intensity has defenders. Serrano and Muñoz compared three courses of the same 110 hours: spread over seven months, compressed into three or four, or packed into five weeks at 25 hours a week. The intensive learners did slightly better, though the difference was not statistically significant and there was no delayed test. A larger study of 230 children by Collins and White found no clear advantage either way for 400 hours concentrated into five months or spread over ten, and Serrano later found intermediate learners gained more from intensive programmes than advanced ones.

The fair summary: short daily sessions are an efficient way to hold on to words, while broader proficiency depends heavily on total hours. Fifteen minutes is a floor to build on, and our page on spaced repetition explains how the gaps between reviews should grow.

How long does it take for a daily habit to stick?

Longer than the popular 21 days. In a study by Lally and colleagues at University College London, 96 volunteers chose one eating, drinking or activity habit and repeated it daily in the same setting for 12 weeks. Among those whose data fitted the model, the time to reach 95% of their eventual automaticity ranged from 18 to 254 days, and the UCL team reports an average of 66 days. The upper end is an extrapolation beyond the 84 days actually observed.

Two details are useful for language learners. The habit was always tied to the same context, so pick a fixed slot, such as the morning coffee or the commute home, rather than whenever you remember. And missing one opportunity did not materially affect how the habit formed, so a lost day is no reason to give up.

What fits into 15 minutes of reading?

Marc Brysbaert's review of 190 studies puts adult silent reading in English, in the reader's own language, at about 238 words a minute for non-fiction and 260 for fiction. Second-language readers are considerably slower, and rates below 100 words a minute are not unusual. Paul Nation warns that reading much slower than 100 words a minute can harm comprehension, which is one more reason to read text pitched at your level.

At a modest 100 words a minute, here is what ten minutes of reading covers in Contos, with five minutes left for flashcards:

Ten minutes at 100 words a minute is 1,000 words a day, or 7,000 a week; a full quarter-hour of reading would reach about 10,500. That is in the region of the weekly reading volume discussed on our extensive reading page. Tapping words slows you down at first, so expect fewer chapters in the early weeks.

• Minutes 1–5: review. Clear the flashcards that are due before they pile up.
• Minutes 5–15: read. One new chapter, or reread yesterday's if it still felt hard. Tap only the words that block the story.
• Once a week: go longer. If you have a free half-hour at the weekend, read ahead in a series. Extra time helps; the daily slot keeps the words coming back.