Start with a question:
兄はその雑誌を＿＿。
A. 買いたい B. 買いたがっている C. 買いたかった
The answer is B. 買いたがっている. The subject is「兄」(older brother), not "I" — third person can't use たい, you need たがる.
Prerequisite: Only Volitional Verbs Take たい
Not every verb can take たい.
- ✅ 食べたい (want to eat) — eating is something you can choose to do
- ✅ 行きたい (want to go) — going is within your control
- ❌ 散りたい (want to wither?) — flowers can't choose whether to wither
Rule: Only "volitional verbs" (actions a person can deliberately choose) take たい. Non-volitional verbs like「散る」(wither) or「降る」(rain) can't.
Quick test: if a human can deliberately choose to do it → volitional verb → can take たい.
たい = I Want, たがる = They Want
| たい | たがる | |
|---|---|---|
| Used for | First person (I) | Third person (he/she) |
| Expresses | Inner desire | Observed desire |
| Nuance | I truly want this | They appear to want this |
Why? Because Japanese holds that you can only be certain of your own feelings — others' feelings can only be inferred from observation.
-
私はビールを買いたい。 → I want to buy beer. (I know my own feelings)
-
兄はその雑誌を買いたがっている。 → My brother wants to buy that magazine. (I can see he's showing signs of wanting it)
たがる Is a Verb
たがる is a godan verb, commonly used as「〜たがっている」to show an ongoing visible desire:
-
子供は外で遊びたがっている。 → The child wants to play outside. (You can tell — they're restless)
-
彼女は新しいバッグを欲しがっている。 → She really wants a new bag. (She keeps looking at them)
「欲しい」→「欲しがる」follows the same logic: I want = 欲しい, they want = 欲しがっている.
Self-Test
Q1. 田中さんはその映画を＿＿。(Tanaka really wants to see that movie)
A. 見たい B. 見たがっている C. 見たいと思う
Show answer
B. 見たがっている. Tanaka is third person — can't use たい.
Q2. Is「雨が降りたい」correct?
Show answer
No. 「降る」is non-volitional — rain can't "decide" to fall, so it can't take たい.
Summary
- たい = first person "want to," たがる = third person "want to"
- Only volitional verbs (actions a person can choose to do) take たい
- たがる is a godan verb, commonly used as「〜たがっている」
- 欲しい → 欲しがる follows the same logic