Why does Thai writing have no spaces?

Because Thai marks the boundaries of phrases and sentences rather than of words, using spaces where English would use punctuation. A learner therefore has to segment the stream into words while also decoding unfamiliar letters, which is two problems at once and is the reason Thai reading takes far longer than the size of the alphabet suggests. It resolves with vocabulary rather than with practice: once you know a word you see it, and until you do the line is undifferentiated.

How does the Thai alphabet encode tone?

Not with a simple mark. The tone of a syllable is determined by a combination of which class its initial consonant belongs to, whether the syllable is open or closed, the length of the vowel, and any tone mark present. There are 44 consonant letters distributed across three classes, and the class is not deducible from the shape. This means reading a Thai word aloud correctly requires running a small set of rules rather than reading a symbol, and it is the part of learning to read that takes months rather than weeks.

Is Thai grammar really that simple?

Yes, by the measures English speakers usually worry about. Verbs never change form. There are no plurals, no cases, no grammatical gender and no articles. Tense is expressed with separate words when context does not already supply it. What replaces all of that is a system of classifiers used when counting things, a set of particles that carry politeness and mood, and a register system where word choice shifts with the social relationship — none of which is difficult to understand and all of which takes time to use naturally.

Do I need to learn the Thai script, or can I use romanisation?

Learn the script, and start early. Thai romanisation is not standardised, so the same word appears in several spellings across different sources, and none of them reliably encodes tone or vowel length. A learner who stays on romanised text develops a pronunciation that is systematically slightly wrong and cannot read anything real. The script is a genuine investment — larger than Cyrillic or hangul — and it repays it by being the only representation that contains the information you need.

Does knowing Chinese help with Thai?

Less than people expect, and our model applies no discount. Thai is Kra-Dai and Chinese is Sino-Tibetan, so they are unrelated by descent, and the writing systems have nothing in common. What a Mandarin or Cantonese speaker brings is the habit of treating pitch as part of a word rather than as emotion, which is the single hardest adjustment for a speaker of a non-tonal language. There is also a layer of shared vocabulary from historical contact, mostly in formal registers.

How long does it take to learn Thai?

The US Foreign Service Institute places Thai in its 1,100-hour band and marks it as usually harder than others in that group, which our model prices at about 1,265 class hours to professional proficiency. At an hour a day with a tutor, conversational Thai (B1) takes around two and a half years. The grammar is close to the simplest on this site. Five tones, a 44-consonant alphabet with tone rules built into it, and text written without spaces between words are where the hours go.

FSI baseline: 1100 class hours
Difficulty band: hard
FSI category: Category III / Category IV

Thai sits in the Foreign Service Institute's third tier — 1,100 class hours — and carries FSI's marking for languages usually harder than others in the same group. Our model prices that at about 1,265 hours to professional proficiency.

That extra 15% is our estimate. FSI flags these languages and publishes no separate figure for them.

The two standing warnings:

Those are classroom hours, not app minutes. Full-time small-group instruction with qualified teachers.

These hours are professional proficiency — arguing a point in your field, reading a newspaper unaided.

The grammar is nearly free and the script is not

Thai splits its difficulty more sharply than almost any language here.

Free: no verb conjugation, ever. No plurals. No cases. No gender. No articles. Word order is subject-verb-object. A learner coming from Russian or German will find the sentence structure almost insultingly simple.

Expensive: everything about how Thai is written and how it sounds.

Where the time actually goes

Reading is three problems stacked

The Thai alphabet has 44 consonant letters and a large set of vowel symbols that can appear before, after, above or below the consonant they follow in speech.

That alone would be a few weeks. Two further things make it months:

Tone is computed, not read. A syllable's tone comes from the class of its initial consonant, whether the syllable is open or closed, the vowel length, and any tone mark. The consonant classes are not deducible from the letter shapes; they are memorised. So reading a word aloud correctly means running a short procedure, and doing it at reading speed takes a long time to automate.

There are no spaces between words. Thai uses spaces roughly where English uses punctuation. A beginner therefore has to find the word boundaries and decode the letters simultaneously.

The second problem dissolves as vocabulary grows — once you know a word, you see it in the line — which means early reading practice feels unrewarding in a specific way that is worth expecting.

Five tones, unmarked in speech and computed in writing

The same syllable at five pitch contours is five words. As in every tonal language, the cost is perceptual before it is productive: you cannot make a distinction you cannot hear.

Thai is harder than Vietnamese in this respect, because Vietnamese writes its tones directly and Thai makes you derive them.

What replaces the grammar you were spared

Thai is not effortless above the sentence level. Counting anything requires the right classifier for the category of thing being counted. Sentences carry particles that convey politeness, softening and mood, and leaving them out is not neutral — it is blunt. And word choice shifts with the social relationship in a way that has to be absorbed rather than tabulated.

None of this is conceptually hard. All of it takes time to use without thinking, and it is where the hours the grammar did not consume end up.

What each level actually costs

Goal	Method	Estimate
A2 — simple everyday exchanges	App, 20 min/day	around 632 hours, ~5.2 years
B1 — hold a conversation	Tutor, 1 hr/day, 5 days	around 664 hours, ~2.6 years
B2 — work, study, argue a point	Tutor, 1 hr/day, 5 days	around 970 hours, ~3.7 years
C1 — professional proficiency	Intensive class, FSI-style	1,265 hours, ~12 months full-time

The romanisation trap

Thai romanisation is not standardised. The same word appears in several spellings across guidebooks, menus, street signs and textbooks, and none of the common systems reliably encodes tone or vowel length.

A learner who works from romanised text is therefore learning a version of Thai with the two most important pieces of information removed, and building a pronunciation that is consistently slightly wrong.

The script is a bigger investment than hangul or Cyrillic. It is also the only representation that contains what you need, and every month spent on romanisation is a month of errors to unlearn.

If you already speak a tonal language

Mandarin, Cantonese or Vietnamese speakers arrive having already made the hardest adjustment: treating pitch as part of a word rather than as emotion.

Our model applies no discount, because the languages are unrelated by descent and any coefficient would be invented. The advantage is real anyway, and it is concentrated exactly where Thai is most expensive.

What actually works

Learn the script first and completely. It is slow, it is the gate, and romanisation is worse than useless because it teaches errors.
Drill consonant classes as vocabulary. They are memorised facts, not patterns, and everything about reading tone depends on them.
Expect early reading to feel unproductive. Word segmentation improves with vocabulary, not with effort.
Do not mistake the easy grammar for an easy language. It is the smallest part of the project.

How you study matters more than which language

The same target, the same hour a day, five different ways of spending it.

Hours to B2 in Thai, holding everything else equal. The slowest method that gets there takes 2× the fastest — a wider gap than the one between neighbouring FSI difficulty bands. The hatched bar never arrives at all, however many hours go into it.

Run this for your own pace

Common questions

Why does Thai writing have no spaces?: Because Thai marks the boundaries of phrases and sentences rather than of words, using spaces where English would use punctuation. A learner therefore has to segment the stream into words while also decoding unfamiliar letters, which is two problems at once and is the reason Thai reading takes far longer than the size of the alphabet suggests. It resolves with vocabulary rather than with practice: once you know a word you see it, and until you do the line is undifferentiated.
How does the Thai alphabet encode tone?: Not with a simple mark. The tone of a syllable is determined by a combination of which class its initial consonant belongs to, whether the syllable is open or closed, the length of the vowel, and any tone mark present. There are 44 consonant letters distributed across three classes, and the class is not deducible from the shape. This means reading a Thai word aloud correctly requires running a small set of rules rather than reading a symbol, and it is the part of learning to read that takes months rather than weeks.
Is Thai grammar really that simple?: Yes, by the measures English speakers usually worry about. Verbs never change form. There are no plurals, no cases, no grammatical gender and no articles. Tense is expressed with separate words when context does not already supply it. What replaces all of that is a system of classifiers used when counting things, a set of particles that carry politeness and mood, and a register system where word choice shifts with the social relationship — none of which is difficult to understand and all of which takes time to use naturally.
Do I need to learn the Thai script, or can I use romanisation?: Learn the script, and start early. Thai romanisation is not standardised, so the same word appears in several spellings across different sources, and none of them reliably encodes tone or vowel length. A learner who stays on romanised text develops a pronunciation that is systematically slightly wrong and cannot read anything real. The script is a genuine investment — larger than Cyrillic or hangul — and it repays it by being the only representation that contains the information you need.
Does knowing Chinese help with Thai?: Less than people expect, and our model applies no discount. Thai is Kra-Dai and Chinese is Sino-Tibetan, so they are unrelated by descent, and the writing systems have nothing in common. What a Mandarin or Cantonese speaker brings is the habit of treating pitch as part of a word rather than as emotion, which is the single hardest adjustment for a speaker of a non-tonal language. There is also a layer of shared vocabulary from historical contact, mostly in formal registers.

Where to study Thai

Matched by the same rules the calculator uses, at a B1 target with no prior related language. The rules were written before any of these were added and the ranking code cannot read commission rates — a test rewrites every payout and checks the order does not move.

AnkiFree · Structured self-study course · up to C2earns us nothing
Anyone who needs to retain vocabulary — free, and better at spaced repetition than every paid app.
Not for: People who want a curriculum — Anki is a tool, not a course
Language ReactorFree · Structured self-study course · up to C1earns us nothing
Intermediate learners who want native input from video with dual subtitles, at no cost.
Not for: Beginners — unscripted native speech below A2 is noise, not input
Rocket Languagesabout $260 once · Structured self-study course · up to B2
Learners who want one structured course covering grammar explicitly, bought once rather than rented.
Not for: Anyone who wants live correction from a human — this is a recorded course
Pimsleurabout $150 once · Structured self-study course · up to B1
Learners who want to speak from the first lesson and can give it thirty focused minutes of audio a day, hands-free.
Not for: Anyone who wants to read or write the language — the method is almost entirely spoken

Your own target and budget change this list — run it for your case. Prices carry the date they were checked and go stale; confirm on the merchant's own site before paying.

Sources

Where the baseline figure on this page comes from. Everything applied on top of it is our own estimate.

Foreign Language Training — US Department of State, Foreign Service Institute
The class-hour bands every estimate on this site starts from, and the definition of the proficiency they lead to (ILR Speaking-3 / Reading-3).
FSI Language Difficulty Ranking — fsi-language-courses.org
Which languages sit in which band. The State Department publishes the categories as an image, so per-language assignment comes from independent reproductions that agree with each other and with the official hour bands.

By Kevin Fan. Native Mandarin speaker who learned English as a second language — the same pairing this site prices at 2,200 hours, done from the far side. Builds and maintains the estimate model and every page on it. Last reviewed 2026-08-08. How we work these numbers out, including which coefficients are our own estimates.