Overview
English “want” does two jobs with one word — “I want a car” (a thing) and “I want to drive” (an action) — but Japanese splits them. がほしい is for wanting a thing (a noun): 車がほしい (“I want a car”). たい is for wanting to do something (a verb action): 運転したい (“I want to drive”). So before you say “want,” ask: is the thing I want a noun or an action? Noun → ほしい; action → たい. The shorthand for students: ほしい = “want [a thing]”; たい = “want to [do]”. Two more facts bind the pair together: both ほしい and たい are grammatically い-adjectives (so they conjugate ほしくない／ほしかった, たくない／たかった, not like verbs), and both normally describe your own wants — for someone else’s, you switch to ほしがる／たがる. They confuse learners because the single English “want” gives no hint which one to use, and because their い-adjective endings look nothing like the verb they came from. The sections below split it cleanly. The entries lead with a simple example, then a funny one.
がほしい — “want (a thing)”
Explanation
がほしい expresses that you want a noun — an object, a thing, a state you’d like to possess. 新しいスマホがほしい (“I want a new smartphone”); 時間がほしい (“I want [some] time”). The desired thing is marked with が: [noun] が ほしい. The word ほしい itself is an い-adjective meaning “wanted / desired,” so it behaves like one in every way — ほしい (want), ほしくない (don’t want), ほしかった (wanted), ほしくなかった (didn’t want), and politely ほしいです / ほしくないです.
Grammatically, two points matter. First, the particle is が, not を — ✗ 車をほしい is a classic error; standard Japanese is 車がほしい. Second, ほしい describes the speaker’s desire in statements and the listener’s in questions: 私は犬がほしい (“I want a dog”), 何がほしいですか (“What do you want?”). You cannot flatly say a third person’s want with plain ほしい — 弟は本がほしい sounds wrong as a bare statement. For that, Japanese uses ほしがる／ほしがっている (“show signs of wanting”): 弟は新しいゲームをほしがっています (“My little brother wants a new game”). Note that with ほしがる the object flips to を.
The register is neutral and everyday. The teaching anchor is wanting a noun: ほしい takes a thing marked with が, and it conjugates like an い-adjective. It differs from たい, which wants an action. If what you want is a thing, がほしい is the fit.
Examples
寒いから、あたたかいコートがほしいです。 — It’s cold, so I want a warm coat.
🎂 たんじょうびに、母が「何がほしいですか」と聞きました。私は「時間とお金がほしいです」と答えました。母は「その二つは、私もほしいです」と言いました。 — On my birthday, my mom asked, “What do you want?” I answered, “I want time and money.” My mom said, “Those two — I want them too.”
Common mistake
Don’t mark the wanted thing with を, and don’t conjugate ほしい like a verb. ✗ 水をほしい should be 水がほしい (the particle is が). ✗ ほしいません or ✗ ほしいじゃない should be ほしくないです or ほしくありません (ほしい is an い-adjective, so its negative is ほしくない). And don’t use plain ほしい for someone else’s want — ✗ 妹は犬がほしい as a bare fact should be 妹は犬をほしがっています.
たい — “want to (do an action)”
Explanation
たい expresses that you want to do an action — it attaches to a verb. 日本へ行きたい (“I want to go to Japan”); 寿司が食べたい (“I want to eat sushi”). You form it from the verb’s ます-stem plus たい: 飲む → 飲みます → 飲みたい, 食べる → 食べます → 食べたい, する → したい, 来る → 来(き)たい. Like ほしい, たい is an い-adjective, so it conjugates the same way: たい (want to), たくない (don’t want to), たかった (wanted to), たくなかった (didn’t want to), politely たいです / たくないです.
Grammatically, note the object particle: with たい you may mark the object with を or が — 水を飲みたい and 水が飲みたい are both fine, with が putting a little more focus on the thing you crave and を sounding neutral. The person rule is the same as ほしい: たい is for the speaker in statements and the listener in questions (何が食べたいですか, “What do you want to eat?”). For a third person’s desire to act, use たがる／たがっている: 妹は日本へ行きたがっています (“My little sister wants to go to Japan”).
The register is neutral and everyday. The teaching anchor is wanting to do: たい builds off a verb’s ます-stem and conjugates like an い-adjective. It differs from ほしい, which wants a thing. If what you want is to perform an action, たい is the fit.
Examples
今日は疲れたから、早く寝たいです。 — I’m tired today, so I want to go to bed early.
🛌 週末は、何もしたくないです。一日中ねたいです。でも、おなかがすきます。ピザも食べたいです。ねたいですが、食べたいです。とてもむずかしいです。 — On the weekend, I don’t want to do anything. I want to sleep all day. But I get hungry. I also want to eat pizza. I want to sleep, but I want to eat. It’s very difficult.
Common mistake
Don’t attach たい to the dictionary form, and don’t conjugate it like a verb. ✗ 食べるたい is wrong; build it from the ます-stem: 食べ + たい = 食べたい. ✗ 行きたいません should be 行きたくないです (“I don’t want to go”) — たい is an い-adjective, so its negative is たくない. And, as with ほしい, use たがる for others: ✗ 兄は行きたい as a flat statement should be 兄は行きたがっています.
How to choose
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