How to choose which language to learn

Criteria that do not work

“The most useful”

Usefulness is projected years ahead and is almost always wrong. A language that will be needed “someday” gives no reason to open the app today — and that is exactly what decides the outcome.

“The easiest”

The difference in difficulty between languages is smaller than the difference between “I practice almost every day” and “I practice on weekends”. An easy language you do not need gets abandoned exactly like a hard one.

“It has the most speakers”

A billion and a half speakers will not help if none of them lives in your city.

Criteria that work

• It is spoken around you. Signs, announcements, neighbours, colleagues. Every day is a free reason and free review.
• It is spoken by people who matter to you. A partner's relatives, family, friends. The connectedness motive is one of the few linked to the outcome.
• You like it: how it sounds, how it is written, what kind of people speak it. “I'm interested” is the only thing truly linked to success.
• You need it in the coming months, not years. A trip, a move, a job — a concrete term makes practice urgent.

If there are several options

Take both for a week — ten minutes a day each — and see which you return to without being made to. That is more reliable than any reasoning: your own behavior over a week says more about future motivation than a list of arguments.

Learning two languages from scratch at once is not worth it, especially with similar scripts. The characters tangle, and untangling them costs more than learning them in turn.

What this is based on

Every number above comes from a study, linked next to it. The mark “checked little” means one study stands behind the conclusion — or that researchers still argue about it.

• The people who keep going longest are the ones who find it interesting or genuinely need the language. “I'd be ashamed to quit” and “there is something in it for me” do not help at all.checked many times
  Alamer et al., 2025, Educational Psychology Review · Correlation with success: interest and importance r = 0.23; guilt −0.06; external reward −0.01.
• Deciding exactly when and where helps more than deciding to study at all. “After my morning coffee, in the kitchen, ten minutes” works; “I really should get to it” does not.checked many times
  Gollwitzer & Sheeran, 2006, Advances in Experimental Social Psychology 38 · 94 trials, more than 8,000 participants, d = 0.65.
• This holds not only in experiments but in ordinary classrooms, with real students.checked many times
  Mawson & Kang, 2025, Behavioral Sciences 15(6):771 · 22 studies, d = 0.54 (confidence interval 0.31–0.77). The authors warn that individual studies disagree widely.

Next

• Why a word list doesn't stickWhy rereading a word list barely works, what helps instead, and when to return to a word so it stays. With a walkthrough of the research.
• How many words you need to knowHow many words to learn to understand a conversation, and how many to read without a dictionary. And why “I know almost all the words” does not yet mean “I understood everything”.
• Do streaks and rewards helpWhat is proven about gamification in learning, why rewards for participation undermine motivation, and what is known about streaks — an honest walkthrough with numbers and links.
• Is it too late to start as an adultWhat is known about the critical period: the data on 669 thousand people, the criticism of it, and what it means for an adult starting a language from scratch.