〜たい vs 〜てほしい: Who Wants, Who Acts

English packs two very different wishes into one verb. "I want to go" and "I want you to go" both start with "I want," and the difference — who actually does the going — hides inside the grammar. Japanese refuses to hide it. It uses two separate constructions, and which one you reach for depends on a single question: is the wanter the same person as the doer? If you want to perform the action yourself, you use 〜たい. If you want someone else to perform it, you use 〜てほしい — and you mark that someone with に. Getting this split wrong produces the classic calque ×あなたを来たい ("I want you to come"), which no Japanese speaker would ever say.

〜たい: my own action

〜たい attaches to a verb's stem (the ます-form minus ます) and means "I want to [verb]." Crucially, the wanter and the doer are the same person — by default, the speaker.

Notice that 〜たい then conjugates like an い-adjective, not like a verb: 飲みたい (want to drink) → 飲みたくない (don't want to) → 飲みたかった (wanted to) → 飲みたくなかった (didn't want to). The last example above shows 〜たかった, the past. The object of desire can be marked with either が or を (冷たいものが飲みたい ~ 冷たいものを飲みたい); which one and why is drilled on the が with 好き・ほしい and を vs が with 〜たい pages — here just register that both occur.

The third-person trap: 〜たがる

Here is an honest difficulty English hides entirely. 〜たい reports an inner feeling — a desire — and Japanese is cautious about asserting what is going on inside someone else's head. So you cannot flatly say ×弟は行きたい ("my brother wants to go") as a plain statement. For an observed third-person desire, Japanese switches to 〜たがる ("shows signs of wanting"), usually in its 〜たがっている form.

So 〜たい is really first-person (in statements) and second-person (in questions: 何が食べたい？ "what do you want to eat?"), while a third party's wish rides on 〜たがる. This is not a rule you can transfer from English — it comes from the Japanese instinct that feelings are directly knowable only for yourself.

〜てほしい: someone else's action

When you want another person to do something, you build on the て-form plus ほしい: 来て + ほしい = 来てほしい ("[I] want [you] to come"). The person whose action you desire is marked with に.

Line up the minimal pair and the whole system snaps into focus. 私が行きたい — I want to go, I do the going. 田中さんに行ってほしい — I want Tanaka to go, Tanaka does the going. Same wish "I want going to happen," but the doer flips, and the grammar flips with it: 〜たい with no に when I act, 〜てほしい with a に-marked agent when someone else acts.

One subtlety: when the wanted event is a natural happening rather than a person you are directing, the embedded subject stays が, not に — because there is no agent to point at.

Why に? The benefactive frame

Here is the insight that ties it together. 〜てほしい is not really "want [someone] [to do]" — it is built on the giving-and-receiving frame, closer to "want [the doing] done for me." The て-form names an action, and ほしい says you want that action to come your way as a favour. That is exactly the logic of くれる, "give (to me)," and it is why the actor is marked with the same benefactive に you meet with くれる: 田中さんに教えてもらう ("get Tanaka to teach me"), 田中さんに教えてほしい ("want Tanaka to teach me"). The に flags the source of the favour flowing toward you. Once you see 〜てほしい as "I want it done for me," the に stops being arbitrary — it is the giver of the favour.

This also explains why 〜たい cannot take a separate に-agent: there is no favour flowing from anyone, because the wanter is already the doer. The favour frame simply has no room for a second party.

Negatives and politer variants

To wish that someone not do something, negate the inner verb with 〜ないでほしい:

〜てほしい is direct, so toward someone above you it can feel presumptuous. The graded, politer alternatives run 〜てほしい → 〜てもらいたい → 〜ていただきたい, each more deferential:

Quick decision guide

Common mistakes

Mistake 1 — Calquing "I want you to come" with 〜たい. English "want you to" tempts learners to keep 来たい and bolt on a "you." But 来たい can only mean "I want to come"; there is no slot for a second doer.

Mistake 2 — Marking the 〜てほしい agent with を or が. Because English says "want him to help," learners reach for the object marker を — but 田中さんを手伝ってほしい means "I want [someone] to help Tanaka." The person you want to act takes に.

Mistake 3 — Stating a third person's wish with plain 〜たい. Japanese won't let you assert someone else's inner feeling flatly; use 〜たがっている.

Mistake 4 — Asking a superior 〜たいですか. "Do you want…?" as 〜たいですか is too blunt and even prying toward someone above you (department heads included).

Mistake 5 — Attaching ほしい to the wrong form. 〜てほしい needs the て-form, not the dictionary form or the bare stem.

Key takeaways

• 〜たい = my own action; the wanter and doer are the same person, so it takes no separate agent.
• 〜てほしい = someone else's action; the person you want to act is marked with に.
• The に is the benefactive に — 〜てほしい means "want it done for me," the same favour-frame as くれる.
• A third party's wish is reported with 〜たがる/〜たがっている, not plain 〜たい.
• To choose, ask "who does the action?" — me → 〜たい, someone else → 〜てほしい.