Japanese has exactly two irregular verbs, and they are the two most useful verbs in the language: する (to do) and 来る (to come). Their te-forms are して (shite) and 来て (read kite, きて). No rule generates these — you memorize them directly — but the payoff is enormous, because する powers hundreds of compound verbs and 来る powers the whole family of "come and…" motion helpers.
する → して
The verb する becomes して. Nothing about the dictionary form hints at this shape, so treat it as a fixed pair to be learned by heart: する → して.
宿題をしてから、ゲームをした。
shukudai o shite kara, gēmu o shita
I did my homework and then played video games.
窓を開けて、掃除をしているところです。
mado o akete, sōji o shite iru tokoro desu
I've opened the window and I'm right in the middle of cleaning.
する drives every compound built on it
This is why して repays learning so richly. A vast number of Japanese verbs are a noun + する, and every single one forms its te-form by turning that する into して. Learn one irregular form and you unlock the entire family.
| Compound verb | te-form | Reading |
|---|---|---|
| 勉強する (to study) | 勉強して | benkyō suru → benkyō shite |
| 電話する (to phone) | 電話して | denwa suru → denwa shite |
| 運動する (to exercise) | 運動して | undō suru → undō shite |
| 予約する (to reserve) | 予約して | yoyaku suru → yoyaku shite |
| 心配する (to worry) | 心配して | shinpai suru → shinpai shite |
毎日日本語を勉強しています。
mainichi nihongo o benkyō shite imasu
I study Japanese every day.
着いたら電話してね。駅まで迎えに行くから。
tsuitara denwa shite ne. eki made mukae ni iku kara
Call me when you arrive. I'll come pick you up at the station.
少し運動して、いい汗をかいた。
sukoshi undō shite, ii ase o kaita
I got a bit of exercise and worked up a good sweat.
来る → 来て (kite, not kuru-te)
The verb 来る becomes 来て, and here is the trap that pure romaji study hides completely: the kanji 来 stays put while its reading changes. In the dictionary form it reads ku, but in the te-form it reads ki. So 来て is きて (kite) — never kuru-te, never kite spelled from 来 as if it kept the ku sound.
| Form | Kanji | Reading |
|---|---|---|
| Dictionary | 来る | kuru |
| te-form | 来て | kite |
| Negative | 来ない | konai |
| Polite | 来ます | kimasu |
| Past | 来た | kita |
The reading skates across ku → ki → ko while the character 来 never moves. This is unique to 来る, and it is exactly the kind of thing a learner who only reads romaji will get wrong, because the romaji throws away the very ambiguity you need to notice. Whenever you see 来て, say kite to yourself.
早く来て！みんなもう待ってるよ。
hayaku kite! minna mō matteru yo
Come quick! Everyone's already waiting.
昨日、友達がうちに来て、一緒に映画を見た。
kinō, tomodachi ga uchi ni kite, issho ni eiga o mita
Yesterday a friend came over and we watched a movie together.
駅まで迎えに来てくれる？
eki made mukae ni kite kureru?
Could you come pick me up at the station?
来る drives the "come and…" helpers
Just as する builds noun-compounds, 来る builds motion compounds where a te-form verb is followed by 来る to mean "do something and come (back)." When 来る goes to its te-form inside these, it becomes 来て — again read kite.
帰りに牛乳を買ってきてくれる？
kaeri ni gyūnyū o katte kite kureru?
Could you buy some milk and bring it back on your way home?
妹も連れてきていい？
imōto mo tsurete kite ii?
Can I bring my little sister along too?
The direction contrast (going away with 〜ていく versus coming back with 〜てくる) is covered on its own page: see movement with 〜ていく／〜てくる.
Comparison with English
English marks irregular verbs by changing the vowel inside the word ("come → came," "do → did"), and the spelling changes with the sound. Japanese 来る does the opposite: the written character is frozen and the reading shifts underneath it. There is no English habit that prepares you for a word that looks the same on the page while sounding different in each form. The only defense is to bind the reading to the form directly in memory: 来て = kite, 来た = kita, 来ない = konai.
する, by contrast, has no useful English parallel at all — it is simply the language's all-purpose "do" verb, and its irregular して must be learned as a single fact and then reused everywhere.
Common mistakes
❌ 早くくて！みんな待ってるよ。
hayaku kute! minna matteru yo
Incorrect — the te-form of 来る is not built from kuru; ×くて does not exist.
✅ 早く来て！みんな待ってるよ。
hayaku kite! minna matteru yo
Come quick! Everyone's waiting.
Deriving the te-form from the kuru sound (kuru → ×くて) is the classic 来る error. The reading shifts to ki, so it is 来て = kite — lock that in.
❌ 宿題をするて、寝た。
shukudai o surute, neta
Incorrect — there is no regular ×するて; する is irregular → して.
✅ 宿題をして、寝た。
shukudai o shite, neta
I did my homework and went to bed.
Do not invent a regular-looking form for する. It never behaves like a godan or ichidan verb; the te-form is simply して.
❌ 毎日運動するて、健康になった。
mainichi undō surute, kenkō ni natta
Incorrect — the する in a compound is still irregular → 運動して.
✅ 毎日運動して、健康になった。
mainichi undō shite, kenkō ni natta
I exercised every day and got healthier.
Every noun-plus-する compound inherits して. If you catch yourself writing ×〜するて, the fix is always 〜して.
❌ 荷物を持って来って、ここに置いて。
nimotsu o motte kitte, koko ni oite
Incorrect — 来る is not a godan る-verb; it never doubles to ×来って.
✅ 荷物を持ってきて、ここに置いて。
nimotsu o motte kite, koko ni oite
Bring the luggage over and set it down here.
Because 来る ends in る, learners sometimes force the う・つ・る pattern onto it (×来って). It is irregular, not godan — the te-form is 来て.
Key takeaways
- する → して and 来る → 来て (kite). These are the only two irregular verbs.
- Every noun + する compound (勉強する, 電話する, 運動する…) forms its te-form with して.
- 来る keeps the kanji 来 fixed while its reading shifts: 来る kuru / 来て kite / 来ない konai / 来ます kimasu.
- The "come and…" helper 〜てくる uses this 来て, usually written in kana (買ってきて).
- Neither verb takes any euphonic change — you memorize the forms, you don't derive them.
Now practice Japanese
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Start learning Japanese→Related Topics
- Ichidan (ru-verbs): drop る, add てN4 — How ichidan verbs form the te-form by simply dropping る and adding て — the easy class with no euphonic changes, plus how to tell them from look-alike godan verbs.
- The te-form Song: All Rules on One PageN4 — The complete te-form system on a single page, built around the classic learner mnemonic — う・つ・る→って, む・ぬ・ぶ→んで, く→いて, ぐ→いで, す→して, plus ichidan and the two irregulars.
- 〜ていく／〜てくる: Motion with an ActionN3 — How te-form + いく／くる attaches physical direction to an action — いく moves away from the speaker, くる moves toward them and often frames a there-and-back round trip anchored to where the speaker stands.
- The て-form: Japanese's Universal ConnectorN4 — Why the tenseless, politeness-free て-form is the single most productive conjugation in Japanese — the hinge that feeds requests, progressives, sequence, permission, and dozens more constructions.