Preply English Tutoring vs Duolingo Korean
Same Bayesian formula, same rubric — so the difference in scores reflects the difference in the courses, not the difference in how we evaluated them.
Preply · Languages
Preply English Tutoring
Duolingo · Languages
Duolingo Korean
Per-criterion
Preply has no curriculum of its own — content quality is whatever the English tutor brings to each session. Many tutors build a tailored lesson plan after the trial around a learner's target (IELTS, business English, conversation, accent work), which gives Preply slightly more structure than a pure pay-as-you-go board. The ceiling is high, but the floor depends on careful tutor selection, and reviewers note there is no built-in tool to check your level of English between lessons.
The English pool is enormous — over 40,000 tutors spanning certified teachers and native community tutors from the US, UK, South Africa and beyond. A well-chosen tutor is repeatedly named the single highest-leverage decision. The catch is vetting: anyone can sign up to teach, Preply does not control what or how tutors teach, and reviewers flag some profiles claiming native-speaker status who clearly are not, so screening via the trial lesson falls on the learner.
English is one of Preply's deepest and cheapest markets — classes start around $2 and native US/UK tutors typically sit in the $20-30/hour range. Value is dented by the package model: lessons are bought as subscription credits up front rather than one at a time, and unused credits do not always carry over. For committed weekly learners the per-lesson math is strong; for casual or irregular learners the credit model creates friction.
The subscription/weekly-credit model is the most polarising feature, and it cuts both ways on retention. Learners who pre-commit to a recurring slot describe it as the most durable English habit they built — committing to a schedule means flaking less, and the easy booking flow curbs procrastination. Learners with busy, rotating schedules find the same model strict, and several flagged auto-renewal and expiring credits as a drag. Net positive for habit formation, friction for irregular schedules.
Scheduling, messaging and tutor-matching are reported as smooth, and the free-trial-replacement flow (a second trial with a different tutor if the first disappoints) is praised. The weak spot is billing and cancellation: the cancellation window is strict, and a recurring complaint across user reviews is being charged after cancelling or struggling to stop the subscription. This is the most-cited support frustration.
The clearest strength. Regular 1-on-1 conversation with a native or near-native English speaker is the most direct route from app-bound recognition to real speaking, and learners describe sessions cementing pronunciation, fluency and confidence they could not build alone. The format exposes gaps — speaking at speed, listening to a real accent, handling interview or IELTS-style prompts — that apps never surface, and tutors adapt vocabulary to each learner's actual goals.
The Hangul onboarding is the strongest part — the 24 letters are introduced gradually inside real words, and most reviewers can read basic Hangul within a week or two. Beyond that, the Korean tree is noticeably smaller and less developed than Spanish: roughly 65 skills over three checkpoints, topping out around TOPIK Level 2 (CEFR A2). Particles, conjugation, and the honorific system — the things that make Korean hard — are presented as patterns to absorb rather than concepts to understand.
There is no instructor; the method is implicit pattern-matching. For a SOV language with particles and multiple politeness levels, the hands-off approach is a real weakness. Reviewers note the course throws sentences at you and expects you to induce the rules, and that speech levels like formal-polite and polite appear at random without explaining which to use. Korean's grammar diverges far more from English than Spanish does, so the lack of explanation bites harder here.
The entire Korean course is free, which is its clearest strength — zero-cost Hangul exposure and basic vocabulary with no commitment. Super Duolingo (~$7-13/month) removes ads and adds hearts but does not fill the structural gaps, so reviewers agree the value lives almost entirely in the free tier. The unpaid experience is heavily ad-interrupted, which several Korean learners called out as frustrating, but the price-to-content ratio at zero is still favourable for a beginner.
The streak engine, XP, and reminders work as well for Korean as for any other course — they build a genuine daily habit and are the most common reason reviewers credit Duolingo with keeping them studying at all. The smaller Korean tree means motivated learners reach the end of meaningful content faster than in Spanish, and the well-documented A2 plateau arrives sooner, where recognition keeps improving but real ability stalls.
Duolingo support is email-only, slow, and community-forum-led, and the Korean course has less external community coverage than the flagship European languages. Billing, streak-recovery, and account issues are the usual pain points. The smaller learner base means fewer third-party explainers to fall back on when the in-app notes are thin.
This is the weakest area, and Korean exposes it sharply. Speech exercises use unreliable voice recognition, there is no spontaneous production, and the honorific system that governs almost every real Korean interaction is barely explained. Multiple reviewers describe studying Korean on Duolingo for a year and being unable to do more than greet a native speaker. It builds receptive vocabulary, not conversational ability.
Scoring methodology applies identically to every course on the site — see the formula.