If you are weighing a Preply tutor, you have probably seen the headline numbers. Preply’s 2025 study, run with Leanlab Education, found that learners who took 24 or more lessons over 12 weeks improved their CEFR level about three times faster than typical learning timelines, and that roughly one in three moved up a full level in just 12 weeks. That is a strong result, and it points to something real: consistent, live tutoring works.

It also points to the catch. That result required 24-plus lessons in 12 weeks, roughly two lessons a week, every week, with a tutor whose hourly rate you are paying every time. For a lot of serious learners, the limiting factor is not whether a tutor would help. It is whether their schedule and budget can sustain the lesson frequency those results depend on, and what happens to their practice in the weeks that frequency slips.

What Preply is built to do

Preply describes itself as a human-led, AI-enabled tutoring marketplace, and it operates at real scale: more than 100,000 tutors across 180-plus nationalities, serving learners in more than 180 countries, with a 4.8 rating from tens of thousands of App Store reviews. Unlike a pay-per-lesson platform, Preply works on a subscription tied to one specific tutor: after a paid trial lesson (25 or 50 minutes), you choose one to five lessons a week and pay a recurring fee every 28 days, based on that tutor’s own hourly rate. There is no fixed platform-wide price; tutors set their own rates, and Preply’s own materials cite a typical range of roughly $1 to $50 a lesson, though realistic rates for most learners depend on the language.

The core offering is live, one-on-one video lessons where the tutor adapts every session to your stated goals rather than following a platform-set curriculum, plus supplementary AI tools (Lesson Insights, Daily Exercises, spaced vocabulary review) that sit alongside the tutoring rather than replacing it. Preply’s satisfaction guarantee is notable: if a trial lesson doesn’t work out, you can switch tutors for free or get a refund.

The trade-off is cost and consistency, and it is a trade-off Preply’s own data illustrates rather than hides. The 3x-faster result came from learners who sustained 24-plus lessons over 12 weeks, roughly two a week. At even a modest $25-a-lesson rate, one lesson a week already runs about $100 a month, and two runs close to $200. There is also no fixed curriculum: quality and structure depend entirely on the tutor you choose, and if your lesson frequency drops for a few weeks (a busy season, a tutor’s limited availability), there is no self-paced structure filling that gap. The 2025 study itself was conducted on English learners; Preply does not state how the findings generalize to Spanish, French, or Hebrew specifically.

What Dioma is built to do

Dioma is built to be the thing that does not depend on booking anyone. It is a self-paced subscription platform for intermediate and advanced learners (roughly A2 to C1) across Spanish, French, and Hebrew, with a 751-topic curriculum written by professional language educators and mapped to CEFR sub-levels. You are placed at your level in the first hour, and the system pulls each lesson from that curriculum based on your progress, then gives corrective feedback on your own speaking and writing, available whenever you have a session to spare rather than only when a tutor is free.

That structure is available at a flat cost regardless of how often you use it: $29 a month, or $13 a month billed annually, with a 7-day free trial. Compared to even one weekly tutor lesson at a modest rate, that is a lower and more predictable monthly cost, though it buys a different thing. Dioma has no live human conversation partner. Its corrective feedback is automated and grounded in its curriculum; it is not a real tutor reading your intent and adapting in the moment, which Preply’s own study suggests matters (97% of surveyed learners said real conversations with a tutor were very important to their progress). If what is missing from your practice is a live conversation with a person who can respond to anything you say, Dioma does not replace that.

How to tell which one fits you

The deciding question is not whether a tutor is more effective than a self-paced platform in the abstract. Preply’s own research suggests it can be, given enough consistency. The real question is whether your schedule and budget support that consistency, and what you want happening in the gaps.

Choose Preply if: you want live, personalized instruction from a consistent tutor, your budget supports at least one or two lessons a week, and you value a human who can adapt to your goals and give real-time feedback and encouragement.

Choose Dioma if: you want structured, self-paced practice at a flat, predictable cost, you want feedback the moment you finish an exercise rather than at your next booked lesson, or your schedule cannot reliably sustain the lesson frequency tutoring’s best results depend on.

Use both, in combination, if you want Preply’s live conversation and personal accountability alongside Dioma’s structured practice in between sessions, so the weeks a tutor is not available are not weeks your practice stops entirely.

“Preply’s own research shows tutoring works when you show up consistently. The honest question isn’t whether a tutor helps. It’s whether your schedule and budget support the lesson frequency that consistency actually requires. Geoff Bloom, founder of Dioma”

Where Dioma fits alongside a tutor

Dioma is built to deliver flexible practice for intermediate learners, specifically focused on speaking and writing skills.

Preply’s own data makes a great case for tutoring: consistency with a real person produces real, measurable results. What that data does not solve is what happens in the weeks that consistency slips, or for the learner whose budget only stretches to an occasional lesson rather than two a week. A tutor works like a personal trainer: the sessions are where an expert watches your form, but the progress compounds through what you do between them. Dioma is not trying to be the live conversation partner Preply provides. It is built to be the practice that keeps happening regardless, so a tutor relationship (Preply or otherwise) is reinforcing progress you are already making, not the only place progress happens.

Frequently asked questions