Thomas’s Classroom is a free English course for adults, from complete beginner (A0) to advanced (C1). It has more than a hundred lessons, a placement test, daily practice, the 400 most common words with Portuguese and Spanish notes, and more than nine hundred audio recordings. It is built and run by one teacher.
That is only possible with help from artificial intelligence. Learners and tutors often ask how AI is used here, and whether they can trust what they read and hear. This note answers both questions plainly, and ends with advice on using AI tools in your own English practice.
The short version
- Every voice on the site is a recording made with ElevenLabs, an AI voice company. The recordings are made in advance and saved as ordinary audio files.
- AI helps write the site and first drafts of practice material. A teacher decides what each lesson teaches, in what order, and what the examples should practice.
- Nothing you type is sent to an AI. There are no accounts, no chatbot grading your answers, and your practice history stays on your own device.
The voice: ElevenLabs recordings, never a robot voice
When you press 🔊 Hear it in a lesson, in Word Lab, or on the most common words pages, you hear a recording made with ElevenLabs. Everything you hear, from single words to the Listening Lab scenes, uses one voice, called Avery. Sentences use ElevenLabs’ Multilingual v2 model; single words use a model that is told the text is English, so a word like “van” is never read as another language. Avery sounds like a calm American teacher, speaks at a natural speed, and says each sentence the same way every time you play it.
A few choices are deliberate:
- Recorded once, played many times. Each sentence is recorded ahead of time and saved as a small audio file. When you press play, your phone simply plays that file. The page never contacts ElevenLabs, so the audio works the same for everyone, and nothing about you is shared.
- No browser voice. Many free sites use the robotic voice built into your browser, which changes from phone to phone and often stresses words in the wrong place. If a sentence here does not have a recording yet, it does not get a play button. We would rather show no audio than the wrong model.
- Recorded on a paid plan. ElevenLabs gives a commercial license only for audio made on a paid plan, so every recording on the site was made on one.
The goal is a clear model you can copy. Listen, pause, and say the sentence yourself at the same speed. That habit, sometimes called shadowing, is one of the simplest ways to improve rhythm and pronunciation.
Where AI helps build the site
Thomas’s Classroom is built with an AI coding assistant, Claude, made by Anthropic. It helps in three main ways.
Writing the site itself. The lesson pages, games, Daily Practice, the deck builder for Anki, and the placement test are all code. AI writes much of that code quickly, so one teacher can build tools that would usually need a team.
Drafting practice material. AI drafts examples, gap-fill items, word partners, and first-language notes in the style of each lesson. A draft is a starting point, not the final page. The teacher sets what each lesson must teach and checks that examples are natural, adult, and useful in real conversations.
Checking the work. Before any update goes live, about forty automated checks run over the whole site. They confirm, for example, that every drill has exactly one expected answer, that every link works, that every recording exists, that pages load fast on a phone, and that student-facing text follows the house style. AI is good at writing these checks, and they catch mistakes that a tired human would miss.
What AI does not decide
Some things stay with the teacher.
- What to teach, and when. The curriculum follows the CEFR levels and years of one-on-one teaching: which mistakes adults really make, which grammar they need first, and which topics they actually talk about.
- The method. Every lesson asks you to notice a pattern, practice it, and then use it to say something true about your own life. That design comes from teaching, not from a model.
- The facts behind the word lists. The 400 most common words follow A Frequency Dictionary of Contemporary American English by Mark Davies and Dee Gardner, based on a corpus of real American English. AI did not guess which words are common.
- First-language patterns. The first-language guides describe mistakes that many speakers of a language make, framed as a pattern to check against your own English, never a label.
If you ever find an example that sounds wrong, please tell us. A real person reads every message.
Your privacy
There is no account to create and no AI watching how you learn. Daily Practice, your saved first language, and your Word Lab marks are stored only in your own browser, and you can reset them at any time. If you join the email list, your email address goes to our email provider, not to an AI service.
How to use AI to learn English well
AI tools can help your English a lot, or quietly stop you from improving. A few habits make the difference.
- Use AI voices as a model, then speak. Play a sentence, pause it, and say it out loud. Record yourself and compare. Listening without speaking builds understanding, not fluency.
- Ask a chatbot for examples, not answers. “Give me five natural sentences with I’ve been working” teaches you more than asking it to fix your homework.
- Check grammar explanations against a lesson. Chatbots sometimes explain grammar with confidence and get it wrong. Compare with a structured lesson, such as Present perfect, before you memorize a rule.
- Turn corrections into flashcards. When an AI tool or a tutor corrects your sentence, put the correct sentence on a card. Our note on Anki for English explains how.
- Rehearse real conversations. Before a job interview, a doctor’s visit, or a call to your landlord, ask a chatbot for the five questions you are most likely to hear. Answer each one out loud, then have the real conversation. Our conversation questions work the same way, sorted by topic and level, with role plays for practice with a partner.
- Keep a human in the loop. AI cannot tell you which of your mistakes matter most, or notice that you avoid a tense when you speak. A teacher can. That is what one-on-one lessons are for.
Start here
If you are new, take the free placement test to find your level, or open the curriculum map and start with the first lesson at your level. Ten minutes a day in Daily Practice will bring back what you have studied, just before you forget it.