Godan verb (つ)
役立つやくだつ
yakudatsu役立つ (やくだつ, yakudatsu) — to be useful — is a godan verb ending in つ: 役立って (te-form), 役立った (past), 役立たない (negative), 役立ちます (polite).
It also means to be helpful; to serve the purpose.
How 役立つ conjugates · godan つ-verb
Only the last kana changes: つ becomes た, ち, て or と.
Which one depends on the ending. The five are one line of the hiragana chart — same consonant, vowels あ・い・う・え・お — and everything before that kana never changes.
た役立たないnegative
ち役立ちますpolite present
つ役立つdictionary form
て役立てるpotential役立てばif
と役立とうvolitional
The て and た forms · つ → って, った
っ役立ってte-form役立ったpast
The て and た forms are the only two that don't follow this pattern. Every う-, つ- and る-verb has the same って there.
Aa Dimmed forms are too rare in everyday Japanese for the game to quiz.
PLAIN
| Form | Conjugation | Audio |
|---|---|---|
| present | 役立つ やくだつ yakudatsu | |
| past It was useful. | 役立った やくだった yakudatta | |
| negative It isn't useful. | 役立たない やくだたない yakudatanai | |
| te-form It comes in handy and … | 役立って やくだって yakudatte | |
| past negative It wasn't useful. | 役立たなかった やくだたなかった yakudatanakatta | |
| volitional | 役立とう やくだとう yakudatou | |
| potential | 役立てる やくだてる yakudateru | |
| cond. ば If it's useful, ... | 役立てば やくだてば yakudateba | |
| cond. たら If it comes in useful, ... | 役立ったら やくだったら yakudattara | |
| passive | 役立たれる やくだたれる yakudatareru | |
| causative I make it serve a purpose. | 役立たせる やくだたせる yakudataseru | |
| imperative | 役立て やくだて yakudate |
POLITE
| Form | Conjugation | Audio |
|---|---|---|
| present | 役立ちます やくだちます yakudachimasu | |
| past It was useful. | 役立ちました やくだちました yakudachimashita | |
| negative It isn't useful. | 役立ちません やくだちません yakudachimasen | |
| past negative It wasn't useful. | 役立ちませんでした やくだちませんでした yakudachimasendeshita | |
| volitional | 役立ちましょう やくだちましょう yakudachimashou |
ASPECT
| Form | Conjugation | Audio |
|---|---|---|
| ている It's proving useful. | 役立っている やくだっている yakudatteiru | |
| ていた It was being useful. | 役立っていた やくだっていた yakudatteita | |
| ています It's proving useful. | 役立っています やくだっています yakudatteimasu | |
| ていました It was being useful. | 役立っていました やくだっていました yakudatteimashita |