The ～たい Form: How to Say "Want To Do" in Japanese

To say "want to do" in Japanese with ～たい, start with one rule: attach ～たい to a verb stem to express your own desire to perform that action.¹ The ～たい form itself conjugates like an i-adjective. To talk about what someone else wants, you need a separate form, ～たがる.¹²

Overview

～たい is an auxiliary that attaches to a verb to express the speaker's desire to perform that action: "want to do X."¹ It is core JLPT N5 grammar and one of the first ways a beginner can state a goal or a wish in a full sentence.

The verb desire form ～たい covers wanting to do something. Wanting to have a thing uses a different pattern built on ほしい, so ～たい never attaches to a bare noun.¹

What ～たい expresses

～たい reports a desire to carry out an action, which means it always builds on a verb.¹ Add it to the stem of 食べる and you get 食べたい, "want to eat."

寿司すしが食たべたいです。¹
"I want to eat sushi."

The thing you want is an action, not an object you possess. To say you want a noun itself, Japanese uses [noun] が + ほしい instead. This is a related desire pattern, but not a form of ～たい.¹

日本にほんに行いきたいです。³
"I want to go to Japan."

Because the finished word ends in い, ～たい inflects as an i-adjective. The い changes for tense and polarity, instead of the word conjugating like a verb.¹ That single fact drives the conjugation grid below.

何なにが飲のみたいですか。¹
"What do you want to drink?"

Register and JLPT placement

The bare plain form ～たい (such as 食べたい) is casual and neutral. The polite form simply adds です directly to the い-ending word, giving 食べたいです.³ Both are everyday forms, and ～たいです is the neutral-polite shape used in ordinary polite speech.³

映画えいがが見みたい。¹
"I want to watch a movie." (casual)

映画えいがが見みたいです。³
"I want to watch a movie." (polite)

～たい is grammatically neutral across most registers. Still, stating a bare desire directly to a social superior can sound blunt or demanding. When speaking upward, speakers often soften the statement; those strategies are covered under Nuance and usage contexts.⁴

少すこし休やすみたいです。³
"I want to rest a little."

How to form ～たい

Verb stem + たい

～たい attaches to the verb stem, the 連用形 (ren'yōkei, "continuative form"). The stem is the form left when you remove ます from the polite ～ます form. So if you can already make a verb polite, you can already turn it into a ～たい form.¹³

The formation rule depends on the verb class:

Verb class	Rule	Example
Ichidan (一段, ru-verbs)	Drop る, add たい	食べる → 食べたい (tabetai, "want to eat")
Godan (五段, u-verbs)	Change final -u sound to -i, add たい	飲む → 飲みたい (nomitai); 行く → 行きたい (ikitai); 書く → 書きたい (kakitai)
Irregular する	する → し + たい	する → したい (shitai); 勉強する → 勉強したい (benkyō shitai)
Irregular 来る	来る → き + たい	来る → 来たい (きたい, kitai, "want to come")

来たい is read きたい, not くたい

The stem of 来る (くる) is き, so the desire form 来たい reads きたい. The kanji 来 keeps its appearance but takes the stem reading. Reading it as くたい gives the wrong word.¹

The mechanics are easiest to see as a two-step pipeline: get the stem, then attach the auxiliary.

映画えいがを見みます → 映画えいがが見みたいです。³
"I watch a movie → I want to watch a movie."

友達ともだちに電話でんわしたいです。³
"I want to call a friend."

日本語にほんごを勉強べんきょうしたいです。³
"I want to study Japanese."

たい conjugates as an i-adjective

Because ～たい ends in い, it inflects exactly like an i-adjective such as 高い (takai, "expensive/high"). The final い is replaced for tense and polarity, and ～たい is never conjugated as a verb.¹

The full grid for 飲む → 飲みたい (nomitai):

Form	Plain	Polite
Present (affirmative)	飲みたい (nomitai)	飲みたいです (nomitai desu)
Negative	飲みたくない (nomitakunai)	飲みたくないです (nomitakunai desu) / 飲みたくありません (nomitaku arimasen)
Past	飲みたかった (nomitakatta)	飲みたかったです (nomitakatta desu)
Past negative	飲みたくなかった (nomitakunakatta)	飲みたくなかったです / 飲みたくありませんでした

The polite negative has two accepted shapes: the i-adjective-style ～たくないです and the ～たくありません pattern. Both are correct and current. Use whichever your textbook or speaking partner favors.³

今日きょうは何なにも食たべたくないです。³
"I don't want to eat anything today."

子供こどものころ、医者いしゃになりたかった。¹
"When I was a child, I wanted to become a doctor."

あの映画えいがはあまり見みたくなかったです。³
"I didn't really want to watch that movie."

The て-form and other extensions

As an i-adjective, ～たい takes the i-adjective て-form ～たくて. This form links clauses or supplies a cause or reason, with the sense "wanting to ..., so ...".¹

日本にほんに行いきたくて、お金かねをためています。¹
"I want to go to Japan, so I'm saving money."

The pattern ～たくなる ("come to want to") expresses a change into a state of wanting. It is the i-adjective adverbial ～く + なる applied to たい. This is the same construction that turns 高い into 高くなる ("become expensive").¹

急きゅうに甘あまいものが食たべたくなりました。¹
"I suddenly came to want something sweet."

The を / が particle alternation

Why both を and が appear

With ～たい, the object of the underlying transitive verb may be marked by either を, the usual object marker, or が, the subject and focus marker. Both are grammatical.¹⁵

This alternation arises because ～たい turns the clause into a stative, adjective-like predicate, meaning it describes a state rather than an action in progress. Objects of such stative-transitive predicates (desire, ability, perception, need) are characteristically marked by が rather than を. The same pattern appears with the potential ～できる / ～られる, which belongs to the same predicate class.⁵¹

水みずが飲のみたい。⁶
"I want to drink water."

水みずを飲のみたい。⁶
"I want to drink water."

新あたらしい車くるまが買かいたいです。¹
"I want to buy a new car."

Both markers are common in everyday Japanese. Learners should recognize and accept either with ～たい rather than treat one as an error.¹⁷

The nuance: が emphasizes the object, を is neutral

が foregrounds the object itself, presenting that specific thing as what is wanted. を treats the whole action as the desired activity, without dwelling on the object.⁵⁶ So 水が飲みたい spotlights water specifically, in the sense "it is water I want." By contrast, 水を飲みたい frames "drinking water" as the activity.⁶

コーヒーが飲のみたい。⁶
"I want some coffee." (object foregrounded: it is coffee I want)

が is favored with short, simple predicates where the object sits right next to ～たい. を appears more readily when other words come between the object and the ～たい predicate, especially with longer or more complex objects.⁵⁶

冷つめたいコーヒーをゆっくり飲のみたい。⁵
"I want to slowly drink a cold coffee." (modifiers separate the object from たい, so を)

Tamura's study of the parallel ～できる alternation reports that, in the basic case, either marker is roughly equally available. を is chosen more often as the construction gains agent-like control or the object phrase lengthens.⁵ That finding is reported for ～できる; ～たい patterns the same way as a member of the same stative-transitive class.⁵

何なにが一番いちばん見みたいですか。⁶
"What do you most want to see?" (が highlights the specific thing)

Whose desire? Own vs. others'

～たい is for the speaker (and direct questions)

～たい states an internal psychological state: desire. In Japanese, predicates of internal feeling can be asserted directly only of the first person, the speaker, because the speaker cannot directly know another person's inner state. This is the first-person restriction on psychological predicates.⁸¹

私わたしは寿司すしが食たべたいです。¹
"I want to eat sushi." (first person: fine)

The same restriction permits ～たい with the second person in direct questions, where you ask the addressee about their own desire. The answer comes from the one person who can assert it. That is why 何が食べたいですか is natural.¹

週末しゅうまつ、どこへ行いきたいですか。¹
"Where do you want to go this weekend?" (second person, question: fine)

A flat third-person assertion such as ×彼は食べたいです, read as a plain statement of fact, is unnatural. To report someone else's desire, you must use ～たがる, an evidential form such as そうだ or らしい, or a quotation with と言う.¹⁸

田中たなかさんは何なにを食たべたいと言いっていました。¹
"Tanaka was saying what he wants to eat." (third person allowed inside a quotation with と言う)

～たがる / ～たがっている for third persons

To describe a third person's desire, replace ～たい with ～たがる. Drop the い of たい and add がる, so 食べたい becomes 食べたがる.²⁷ This form is JLPT N4, one step beyond the N5 core of ～たい.²⁷

～たがる is the auxiliary がる ("show signs of ～, appear to ～") attached to the desiderative stem. It conjugates as a godan (う-verb): 食べたがる, 食べたがらない, 食べたがった, 食べたがって.⁷ がる adds an evidential, behavior-based meaning: the third person's desire is inferred from outward behavior, words, or expression, not asserted as direct knowledge of their mind.⁷⁸

The split between the two shapes maps cleanly onto the kind of desire being reported.

～たがっている is the ～ている progressive of たがる. It describes an ongoing, observable desire of a third person. Plain ～たがる leans habitual or general, while ～たがっている describes a present, observed state.²⁷

弟おとうとはもっとゲームをしたがっています。⁷
"My little brother wants to play games more." (observed, ongoing)

子供こどもは外そとに行いきたがる。²
"The child always wants to go outside." (general/habitual)

With ～たがる, the object generally reverts to the normal transitive marker を. The が option of ～たい does not carry over to the がる construction.⁷ This reflects standard textbook treatment rather than a hard-sourced rule, so treat it as the conventional default.

彼かれは新あたらしいパソコンを買かいたがっていました。⁷
"He wanted to buy a new PC." (inferred from his behavior)

～たがる can sound detached about a present person

Because ～たがる frames a desire as outwardly visible, it can carry a faintly detached or critical nuance when used of someone present. For polite hearsay about a specific individual, ～たいようだ or ～たいそうだ are softer alternatives. This nuance follows conventional pedagogy rather than a higher-tier source.⁷

Nuance and usage contexts

Softening and indirectness

A bare ～たい directed at a superior can sound blunt or self-asserting, since Japanese politeness favors hedging one's own desire when speaking upward.⁴

Two common hedges do this work: ～たいと思う / ～たいと思います ("I think I'd like to ...") and ～たいんです, with the explanatory んです. They soften a desire statement by framing it as a tentative thought rather than a flat demand.⁴

来年らいねん、日本にほんに留学りゅうがくしたいと思おもっています。⁴
"I'm thinking I'd like to study in Japan next year." (softened)

ちょっとお聞ききしたいんですが。⁴
"There's something I'd like to ask, if I may." (softened, humble)

少すこし早はやく帰かえりたいのですが。⁴
"I'd like to leave a little early, if that's all right." (softened to a superior)

～たい vs neighboring expressions

～たい (want to do an action, verb + たい) contrasts with [noun] が ほしい (want to have a thing). The two split desire into action versus object, and they are not interchangeable.¹

水みずが飲のみたい。 / 水みずがほしい。¹
"I want to drink water." vs. "I want water."

～たい also differs from the volitional ～(よ)う and the invitation ～ましょう. ～たい states personal desire. The volitional and invitation forms propose an action, often a joint one. So "want to go" (行きたい) is not the same move as "let's go" (行きましょう).¹

海うみに行いきたいです。 / 海うみに行いきましょう。¹
"I want to go to the sea." vs. "Let's go to the sea."

Good to know

The "い ending" hook for conjugation

たい ends in い, so it bends exactly like the i-adjective 高い (takai). The chain 高い → 高くない → 高かった maps directly onto 飲みたい → 飲みたくない → 飲みたかった. Remember "たい is an い-adjective, not a verb," and every tense and polarity follows from a pattern you already know.¹

Stating a third person's desire flatly with ～たい

Learners often try to say "he wants to drink coffee" as 彼はコーヒーを飲みたいです, treating ～たい as a neutral report. As a flat assertion of his desire, this is unnatural. ～たい asserts an internal feeling that Japanese restricts to the speaker (and the addressee in questions). A third person's desire must be marked as inferred, using ～たがる, an evidential form, or a quotation.⁸¹

彼かれはコーヒーを飲のみたがっています。⁷
"He wants to drink coffee." (inferred from his behavior)

Attaching ～たい to a noun

Wanting a thing tempts beginners to write something like ×新しい車たいです for "I want a new car," attaching たい straight to the noun. ～たい needs a verb stem, so this does not parse. To want the thing itself, use [noun] が ほしい. To want to obtain it, use a verb + たい.¹

新あたらしい車くるまがほしいです。 / 新あたらしい車くるまが買かいたいです。¹
"I want a new car." / "I want to buy a new car."

Bare ～たい to a superior

帰りたいです said to a boss can sound abrupt or demanding, because a bare desire asserted upward skips the deference Japanese expects. Soften it with ～たいと思います or ～たいのですが. These forms frame the desire as tentative and deferential.⁴

～たがる is がる, the "shows signs of" auxiliary

Reading ～たがる as desiderative-stem + がる ("appears to want") explains two things at once. First, it is reserved for others because you infer their desire from behavior. Second, it conjugates as a godan verb like 怖がる (kowagaru, "act afraid"). It is the same がる that turns a felt state into an observed one. The surface ～たがる usage rests on conventional pedagogy, while the underlying がる analysis is supported by the work on psychological predicates.⁷⁸

Past ～たかった often implies the want went unfulfilled

行きたかった ("wanted to go") frequently carries a "but couldn't" undertone in real use, reporting a past desire that did not come true. The form itself is just the plain past of ～たい, so context decides whether the wish was met. In practice, the unfulfilled reading is common.¹

See also

• Japanese Giving and Receiving Verbs: あげる, くれる, もらう
• は vs が in Japanese: A Beginner's First Pass
• Transitivity Pairs in Japanese (自他動詞): Intransitive vs. Transitive
• The Te-Form in Japanese: Uses (Linking, Cause, Light Imperative, Continuation)
• Inferential Suffixes in Japanese: ～そう, ～よう, ～らしい, ～みたい Compared

References

Footnotes

1. Makino, Seiichi, and Michio Tsutsui. A Dictionary of Basic Japanese Grammar (日本語基本文法辞典). The Japan Times, 1989. The "～tai" entry. (Tier 4 reference work; standard pedagogical grammar reference.) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³ ↩²⁴ ↩²⁵ ↩²⁶ ↩²⁷ ↩²⁸ ↩²⁹ ↩³⁰ ↩³¹ ↩³² ↩³³ ↩³⁴ ↩³⁵ ↩³⁶ ↩³⁷

2. Banno, Eri, Yoko Ikeda, Yutaka Ohno, Chikako Shinagawa, and Kyoko Tokashiki. Genki I: An Integrated Course in Elementary Japanese, 3rd ed. The Japan Times, 2020. Lesson 11 (desire with ～たい / ～たがる). (Tier 4 reference work.) ↩ ↩² ↩³ ↩⁴ ↩⁵

3. Japanese Introductory 1. Open Educational Resources Collective (OERC), CC BY-NC 4.0. Chapter 9.2, "Expressing Desires with たいです." https://oercollective.caul.edu.au/japanese/chapter/9-2/ (Tier 4 open educational textbook.) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹²

4. 国際交流基金 (Japan Foundation) / 凡人社. 『国際交流基金 日本語教授法シリーズ 第4巻「文法を教える」』 covers register and softening strategies in requests and desire statements. (Tier 4 reference; Japan Foundation teaching-methodology series.) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

5. 田村泰男 (Tamura, Yasuo). 「～が～できる」と「～を～できる」について. 『広島大学留学生センター紀要』(Hiroshima University International Student Center Bulletin), No. 3, 1993, pp. 13–20. https://hiroshima.repo.nii.ac.jp/records/2034867 (Tier 2 peer-reviewed university bulletin; treats が/を object marking under stative-transitive predicates, the same alternation class as ～たい.) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

6. Imabi. "Object Marking: が VS を." https://imabi.org/ga-vs-wo/ (Tier 5, limitation; cites Tamura 1993 ⁵.) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷

7. Tofugu. "Japanese Verb Desire Form たい." https://www.tofugu.com/japanese-grammar/tai-form/ (Tier 5, limitation.) ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹²

8. Kuno, Susumu. The Structure of the Japanese Language. MIT Press, 1973. (Tier 2 academic monograph; the source for the first-person psychological-predicate restriction on internal-state predicates such as desire.) ↩ ↩² ↩³ ↩⁴ ↩⁵