行く
いく
iku
Conjugation
= to go
| Form | Japanese | Romaji | Meaning |
|---|---|---|---|
| Dictionary form The plain form you find in a dictionary |
行く いく |
iku | to go |
| Masu form Polite present / future |
行きます いきます |
ikimasu | go (polite) |
| Te form Connects clauses, makes requests |
行って いって |
itte | go / going (connective) |
| Ta form Plain past |
行った いった |
itta | went |
| Nai form Plain negative |
行かない いかない |
ikanai | not go |
| Masen form Polite negative |
行きません いきません |
ikimasen | not go (polite) |
| Nakatta form Plain past negative |
行かなかった いかなかった |
ikanakatta | did not go |
| Potential form Can / be able to |
行ける いける |
ikeru | can go |
| Volitional form Let’s / I think I’ll |
行こう いこう |
ikou | let’s go |
Iku (行く) breaks the godan te-form rule that other -ku verbs follow. Once you know where the exception sits, the rest of iku conjugates exactly the way a regular godan verb should.
Iku ends in -ku, one of the sounds that mark a verb as godan (the others being -gu, -su, -tsu, -nu, -bu, -mu, -u, and -ru when it is not preceded by an i or e sound). You can confirm the group by negating the verb: godan verbs shift the vowel right before -nai to the a-row, so iku becomes ikanai, not ikinai. An ichidan verb would instead keep its stem unchanged and just add -nai. That vowel shift is the reliable test. Everything about iku follows this godan pattern with one exception: the te and ta forms. A regular -ku verb like kaku contracts to kaite, but iku contracts to itte instead of the expected iite, and the same swap happens in the past tense, where itta replaces iita. This is a fixed, memorized irregularity limited to this one verb’s te/ta forms — it does not move iku into a different verb group, and no other -ku verb behaves this way.
Reach for ikimasu whenever politeness is expected, such as speaking to a stranger, a teacher, or a colleague. The plain iku comes out in casual speech with friends, in your own thoughts, and inside grammar patterns that attach directly to the dictionary form. Ikanai and ikimasen split the same way: ikanai to someone close, ikimasen to someone you’re keeping distance from. Itte is the connector — it links going somewhere to what happens next, whether that’s another action in the same sentence, a request such as itte kudasai, or the set phrase itte kimasu said when leaving the house. Itta reports a completed trip, either as plain past with friends or folded into a larger sentence like itta koto ga aru (have been there before). Ikanakatta is what you reach for telling someone, plainly, that you didn’t end up going. Ikeru turns the sentence from an action into a question of possibility or permission — whether going is doable at all. Ikou is what a speaker uses to propose going somewhere together, on the spot.
Everyday use
明日、スーパーに行ってから晩ごはんを作ります。
Ashita, suupaa ni itte kara bangohan o tsukurimasu.
Tomorrow I’ll go to the supermarket and then make dinner.
Casual / Social Media
今週末、海に行こうよ!
Konshuumatsu, umi ni ikou yo!
Let’s go to the beach this weekend!
Formal / Cultural context
先生、来週の会議には行かれますか。
Sensei, raishuu no kaigi ni wa ikaremasu ka.
Professor, will you be able to attend next week’s meeting?
One mistake is applying the regular -ku pattern and writing or saying iite / iita instead of itte / itta. A second source of confusion is that itta (went, from iku) and itta (said, from iu) are pronounced identically; only context tells them apart, so relying on sound alone in fast speech can point you to the wrong verb entirely. Learners also sometimes try to soften a request with plain itte alone in a formal setting, when itte kudasai (or a more polite request pattern) is what the situation calls for.