Thai is spoken by about 71 million people, most of whom learned it as a second language. Standard Thai. Isan and Northern Thai are not in the native figure, but their speakers are mostly inside the second-language one.
On our measured language map, its closest relatives are Lao, Jingpho and Piedmontese. If you speak one of those, much of the vocabulary will feel familiar from day one.
Structurally, it is written in the Thai script, and the course teaches the writing system letter by letter with pronunciation shown while you learn.
Every lesson is built from 2,000 real Thai sentences, aligned with their translations word by word and piece by piece, so you always see how the sentence actually works instead of memorizing flashcards. The grammar is discovered from the sentences themselves, 1,428 patterns so far, and a spaced-repetition quiz teaches it in the order that unlocks the most of the language first. Our measured estimate for reaching conversational level from English is about 1,152 hours of study. Read how it works.
Most apps only teach Thai through English, if they teach it at all. These starting languages already have a built course, and any other published language can be paired on request:
Speaker figures follow Ethnologue and national censuses, rounded. The difficulty estimate is calibrated against U.S. Foreign Service Institute data.