〜たがる: A Third Person's Desire

English uses one word — wants — for everybody: I want to go, you want to go, my little brother wants to go. Japanese refuses to be that casual about other people's minds. The plain desire form 〜たい is reserved almost entirely for your own wanting (行きたい, "I want to go"). The moment you attribute a desire to someone else, you must switch forms: 弟は行きたがる / 行きたがっている ("my little brother wants to go"). Behind this odd-looking rule sits a piece of cultural logic baked right into the grammar — the idea that you cannot crawl inside another person's head, so you report their desire as something you have observed from the outside. This page shows how 〜たがる is built, what it really means, and why English speakers keep breaking the rule.

The form: たい-stem + がる

Start from the desire form 〜たい. Drop the final い and add がる:

The resulting word ends in -る and behaves as a godan verb (like 分かる, 走る), so it conjugates all the way through: 行きたがる / 行きたがらない / 行きたがった / 行きたがって. That last point matters, because the form you will use most is not the bare たがる but its progressive 〜たがっている (more on that below).

Why the form even exists: you can't read minds

Here is the insight that makes 〜たがる click, and it is genuinely alien to English. Japanese grammaticalizes the assumption that inner states are private. Your own feelings you know directly, so 行きたい ("I want to go") is a plain statement of fact. But another person's feelings you can only infer from what they say and do. So Japanese wraps that inference into the verb itself.

The engine is the suffix がる, which literally converts a feeling-adjective into a verb meaning "to show signs of / to act as if / to behave as though feeling." It is not limited to desire — it works across the whole emotion vocabulary:

So 〜たがる is simply "desire" run through this same がる machine: 行きたがる = "displays the wanting-to-go." You are not claiming to know his heart; you are reporting the outward evidence.

たがる vs たがっている: tendency vs. this moment

The bare non-past 〜たがる and its progressive 〜たがっている are not interchangeable, and the split is subtle but real:

• 〜たがる (bare) leans toward a general tendency or characteristic — "tends to want," "is the sort who wants." It describes a habit or a type, often with a faint whiff of "typically, and a bit annoyingly."
• 〜たがっている describes a specific person wanting right now — the desire is live and currently on display.

When you describe one identifiable person's current wish, 〜たがっている is usually the safer, more natural choice. The bare たがる shines for generalizations (子供は…, みんな…) and habits.

The object leans to を, not が

There is a quiet grammatical consequence of turning desire into a behavior-verb. Plain 〜たい prefers to re-mark its object with が (お菓子が食べたい, "I want to eat sweets"), because たい is adjective-like — see が vs を with desire. But がる makes the whole thing an ordinary transitive verb of behavior, so its object slides back to the plain object marker を:

Notice how the two roles split cleanly in that sentence: the wanters are marked with が (みんなが — the subject of the wanting), while the thing wanted takes を (結果を). This is the opposite of what たい does, and forgetting it is a classic slip.

What about "you"? The second person

If desire is private and 〜たい is for the speaker while 〜たがる is for a third party, where does the listener fall? The clean answer: when you ask someone about their own wish, you use plain 〜たい, because a question hands the feeling back to its owner to report — 行きたい？ ("do you want to go?"). You do not say ×行きたがる to someone's face about themselves; that would describe them from the outside as if they weren't there. 〜たがる enters only once you talk about an absent or third party.

There is one licensed exception worth knowing: in novels and narration, an author who is granted access to a character's inner life may write that character's feelings with plain 〜たい (彼は家に帰りたかった, "he wanted to go home"). The narrator is treated as knowing the heart directly. In ordinary conversation about real third parties, stick with 〜たがる／〜たがっている.

A note on tone: たがる can sound critical

Because 〜たがる reports someone else's desire as observed, persistent behavior, it can pick up a mildly detached or even critical flavor — "he keeps wanting to…," "she insists on…." Describing a respected person's wishes with bare たがる can therefore sound presumptuous or cold. For a superior's desires you would soften with 〜たいようだ / 〜たいらしい ("seems to want to") or reframe entirely. Among family, friends, and children, though, 〜たがる / 〜たがっている is the neutral, everyday way to say what someone else wants.

Common mistakes

This is the number-one transfer error: English uses "wants" for everyone, so learners keep 〜たい for third parties. About someone else, switch to 〜たがる / 〜たがっている.

Key takeaways

• Plain 〜たい is for your own desire; 〜たがる attributes desire to someone else.
• The suffix がる means "show signs of feeling" — 〜たがる literally reports the observed evidence of wanting, encoding that other minds are not directly knowable.
• 〜たがる is a godan verb (negative 〜たがらない, past 〜たがった); use the progressive 〜たがっている for a specific person wanting right now, and bare 〜たがる for a general tendency.
• Its object takes を (お菓子を食べたがる), the opposite of たい's が-preference.
• The same machine gives 欲しがる, 寒がる, 怖がる — all "acts as if feeling X."
• For a superior's wishes, soften to 〜たいようだ／らしい; bare たがる can sound cold.