Tai, Hoshii, te Hoshii: Saying What You Want in Japanese

English expresses desire with one verb — want — and a choice of what follows it: "I want to go", "I want a car", "I want you to go". Japanese splits that into three different constructions, one per shape of wanting:

Learn them as one system and the only genuinely hard part is the rule that runs through all three: you cannot state another person's desire as though it were a fact.

たい (tai): I want to do it

Formation is mechanical: take the ます (masu)-stem of a verb — the part before ます — and add たい (tai).

To negate or put it in the past, conjugate たい like an い-adjective — because that is what it is. It is not a verb, which is the first thing English speakers get wrong.

The object particle shifts too. Verbs normally take を (o) for their object, but with たい (tai) both を and が appear, and が is the more common choice in careful speech:

• 水を飲みたい (mizu o nomitai, "I want to drink water")
• 水が飲みたい (mizu ga nomitai, "I want to drink water")

Both are correct. が tends to foreground the thing wanted — useful when it is the point of the sentence ("water, specifically, is what I want").

ほしい (hoshii): I want a thing

For objects, the pattern is a noun plus がほしい (ga hoshii):

• 新しいカメラがほしい (atarashii kamera ga hoshii, "I want a new camera")
• 時間がほしい (jikan ga hoshii, "I want time")
• お金がほしい (okane ga hoshii, "I want money")

Like たい (tai), ほしい (hoshii) is an い-adjective and inflects the same way: ほしくない (hoshikunai, "do not want"), ほしかった (hoshikatta, "wanted"), ほしくなかった (hoshikunakatta, "did not want"), with です (desu) added for politeness.

ほしい (hoshii) is for things, not actions. If what you want is to do something, you need たい (tai). 本がほしい (hon ga hoshii) is "I want the book"; 本が読みたい (hon ga yomitai) is "I want to read the book". English "I want the book read" splits into one of those two depending on which part matters.

てほしい (te hoshii): I want someone to do it

Put a verb in て-form and add ほしい (hoshii), and the wanting points at another person's action:

• 来てほしい (kite hoshii, "I want you to come")
• もっと日本語を勉強してほしい (motto nihongo o benkyou shite hoshii, "I want you to study more Japanese")
• 手伝ってほしい (tetsudatte hoshii, "I want you to help me")

When you name the person, mark them with に (ni), not を (o):

• 田中さんに来てほしい (Tanaka-san ni kite hoshii, "I want Tanaka to come")
• 子供に早く寝てほしい (kodomo ni hayaku nete hoshii, "I want the kids to go to bed early")

The negative is 〜てほしくない (te hoshikunai, "I don't want you to…"), and past forms follow the adjective rules again: 来てほしかった (kite hoshikatta, "I wanted you to come").

The three side by side

The three form a ladder from private to interpersonal. たい (tai) is a statement about yourself. てほしい (te hoshii) is a statement about someone else's behaviour that they will hear as a request — softer than 〜てください (te kudasai, "please do"), because it reports a wish rather than issuing an instruction.

The third-person rule

This is the part English speakers break constantly, and it is not an arbitrary rule — it reflects how Japanese treats other minds.

You cannot assert someone else's desires directly. 彼は行きたい (kare wa ikitai, "he wants to go") is wrong as a plain statement. It is fine as a question, because a question asks rather than asserts:

• 行きたいですか (ikitai desu ka, "do you want to go?") — fine, you are asking the listener
• 何が食べたいですか (nani ga tabetai desu ka, "what do you want to eat?") — fine

For a third person, you have to mark the desire as an inference or a report:

The 〜たがる (tagaru) form is the most useful one: たがる (tagaru) is the "third-person たい" and conjugates as a normal verb. 子供が外で遊びたがっている (kodomo ga soto de asobitagatte iru, "the kids are itching to play outside").

The same restriction applies to ほしい (hoshii). 彼はカメラがほしい (kare wa kamera ga hoshii, "he wants a camera") is wrong; use 彼はカメラをほしがっている (kare wa kamera o hoshigatte iru, "he's been wanting a camera"). Note that ほしがる (hoshigaru) takes を (o), not が (ga).

And it applies to てほしい (te hoshii) as well — you can only direct it at the person you are talking to:

• 来てほしい (kite hoshii, "I want you to come") — said to you
• 母は私に来てほしいと思っている (haha wa watashi ni kite hoshii to omotte iru, "my mother wants me to come") — wrapped in と思っている (to omotte iru, "is thinking") because it is her wish, reported

Where たい sits in politeness

たい (tai) is a personal, slightly unguarded form. 行きたいです (ikitai desu, "I want to go") is polite enough for most situations, but stating a want can itself be a demand — the same way "I want Friday off" is a statement and "I'd like Friday off" is a request. When you need the softer version, Japanese adds a sentence-final softener:

• 行きたいんですけど (ikitai n desu kedo, "the thing is, I'd like to go…")
• 行きたいな (ikitai na, "I'd love to go") — to yourself or a close friend

And たい (tai) is not used for invitations the way English uses "want". "Do you want to come?" maps to 来ませんか (kimasen ka, "won't you come?") far more often than to 来たいですか (kitai desu ka), which sounds like you are surveying the other person's preferences rather than inviting them.

Common mistakes for English speakers

1. Conjugating たい (tai) as a verb. 行きたいました (ikitaimashita) does not exist. たい (tai) is an い-adjective, so the past is 行きたかった (ikitakatta) and the polite past is 行きたかったです (ikitakatta desu).

2. Stating a third person's wish. 彼は行きたい (kare wa ikitai) or 彼女は車がほしい (kanojo wa kuruma ga hoshii) — both wrong as statements. Add 〜たがっている / 〜ようだ / 〜と言っている, or switch to ほしがっている for objects.

3. Using たい (tai) for objects. "I want a new phone" is not 新しいスマホを食べたい (atarashii sumaho o tabetai) or anything with たい; it is 新しいスマホがほしい (atarashii sumaho ga hoshii). Conversely "I want to buy it" cannot use ほしい — that is 買いたい (kaitai).

4. Marking the person with を in てほしい (te hoshii). 田中さんを来てほしい (Tanaka-san o kite hoshii) is wrong; it is 田中さんに来てほしい (Tanaka-san ni kite hoshii). を marks things, and a person you are wishing an action from is not what を marks here.

5. Attaching ほしい (hoshii) straight to a verb. 来るほしい (kuru hoshii) is wrong; verbs need て-form before ほしい — 来てほしい (kite hoshii).

6. Treating てほしい (te hoshii) as a neutral statement. It is a request wearing a wish's clothes. Said to a superior it can read as pressure. 〜ていただけませんか (te itadakemasen ka, "could you possibly…") is the safer form upward.

7. Asking あなたは〜たいですか too often. It is grammatical, but repeated direct questions about another person's wants feel like an interrogation in a way the English "do you want to…?" does not. Japanese usually invites instead: 一緒に行きませんか (issho ni ikimasen ka, "won't you come with me?").

8. Reading 〜たかった (takatta) as a wish about the future. It is past: 行きたかった (ikitakatta) means "I wanted to go" — often with the implication that I did not. For a future wish, use the present: 行きたい (ikitai, "I want to go").

Summary

Three shapes of wanting, three constructions: 〜たい (tai) for my own actions, 〜がほしい (ga hoshii) for things, 〜てほしい (te hoshii) for someone else's actions. All three inflect like い-adjectives. All three obey one restriction: you may declare your own wants freely, ask the listener about theirs, and must mark anyone else's as observation, inference or quotation — usually with 〜たがっている or 〜ほしがっている.

Wants are where grammar and manners meet, and that is easier to feel than to read about: romaji.live practice puts 行きたい, 行きたがっている and 行ってほしい in real scenes so you type the difference rather than memorise it. Read the polite form first if です (desu) endings are still shaky, see ageru, kureru, morau because 〜てほしい sits right beside 〜てもらいたい, and see tsumori and yotei for the step from wanting something to planning it.