The plain past — the た-form — is the single most efficient conjugation to learn in Japanese, because you get it for free the moment you know the te-form. The rule is almost insultingly simple: take the te-form and swap て → た, で → だ. 書いて → 書いた, 泳いで → 泳いだ, 読んで → 読んだ. Every euphonic change (音便（おんびん）) that the te-form makes, the past makes in lockstep — including the voicing. This page lays out the full た paradigm anchored on 書く → 書いた and shows you exactly where the voicing must carry over.
た is て with the last letter changed
The te-form and the past た-form are the same word with one final kana swapped. Voiceless て pairs with voiceless た; voiced で pairs with voiced だ. That is the whole relationship.
| Verb | te-form | Past た-form |
|---|---|---|
| 書く (kaku) — write | 書いて (kaite) | 書いた (kaita) |
| 泳ぐ (oyogu) — swim | 泳いで (oyoide) | 泳いだ (oyoida) |
| 読む (yomu) — read | 読んで (yonde) | 読んだ (yonda) |
昨日、彼に長いメールを書いた。
kinō, kare ni nagai mēru o kaita
Yesterday I wrote him a long email.
その本、もう読んだ?おもしろかった?
sono hon, mō yonda? omoshirokatta?
Have you read that book yet? Was it good?
The full past た table across every ending
Because た tracks the te-form, its rows group exactly the way the 音便 master chart does: the う・つ・る group doubles to った, the ぬ・ぶ・む group nasalizes to んだ, く/ぐ soften to いた/いだ, す stays した, and 一段 verbs just drop る.
| Ending | Model verb | 音便 type | Past た-form |
|---|---|---|---|
| -う | 会う (au) — meet | 促音便 → った | 会った (atta) |
| -つ | 待つ (matsu) — wait | 待った (matta) | |
| -る (五段) | 取る (toru) — take | 取った (totta) | |
| -ぬ | 死ぬ (shinu) — die | 撥音便 → んだ (voiced) | 死んだ (shinda) |
| -ぶ | 遊ぶ (asobu) — play | 遊んだ (asonda) | |
| -む | 読む (yomu) — read | 読んだ (yonda) | |
| -く | 書く (kaku) — write | イ音便 → いた | 書いた (kaita) |
| -ぐ | 泳ぐ (oyogu) — swim | イ音便 → いだ (voiced) | 泳いだ (oyoida) |
| -す | 話す (hanasu) — speak | no 音便 → した | 話した (hanashita) |
| -る (一段) | 食べる (taberu) — eat | drop る → た | 食べた (tabeta) |
| する | する (suru) — do | irregular | した (shita) |
| 来る | 来る (kuru) — come | irregular | 来た (kita) |
| 行く | 行く (iku) — go | exception → った | 行った (itta) |
友達に会って、二時間も話した。
tomodachi ni atte, nijikan mo hanashita
I met a friend and we talked for two whole hours.
子供の頃、この川でよく泳いだ。
kodomo no koro, kono kawa de yoku oyoida
When I was a kid, I often swam in this river.
The trap: the voicing must carry over
This is where nearly every learner slips at least once. The ぬ・ぶ・む group and the ぐ ending are voiced — they end in だ, not た. 読んだ, not ×読んた; 泳いだ, not ×泳いた; 遊んだ, not ×遊んた. The nasal ん and the historically voiced ぐ "drag" the following た into its voiced twin だ. If your te-form is voiced (で), your past is voiced (だ); no exceptions in this group.
週末、公園で子供と遊んだ。
shūmatsu, kōen de kodomo to asonda
I played with the kids in the park at the weekend.
金魚が死んだって、子供が泣いてる。
kingyo ga shinda tte, kodomo ga naiteru
The kid's crying because the goldfish died.
The irregulars and the one exception
する → した, 来る → 来た（きた）, and the lone 音便 rebel 行く → 行った (not the ×行いた you would expect from a -く verb — see 行く: the te-form exception). These are the same three special cases as in the te-form, because the past just inherits them.
宿題をして、それから寝た。
shukudai o shite, sorekara neta
I did my homework and then went to bed.
今朝は電車が遅れて、遅刻した。
kesa wa densha ga okurete, chikoku shita
The train was late this morning, so I was late.
What the past た-form is used for
Beyond stating a plain past ("I did X"), た is the base for a whole cluster of patterns: 〜たら (conditional "if/when"), 〜たり…〜たりする (listing representative actions), 〜たことがある ("have done before"), and た directly before a noun (a past relative clause: 買った本, "the book I bought"). Learning the た-form well therefore unlocks far more than the simple past.
去年、京都に行ったことがある。
kyonen, Kyōto ni itta koto ga aru
I went to Kyoto last year (I've been to Kyoto).
駅に着いたら、電話して。
eki ni tsuitara, denwa shite
Call me when you get to the station.
Note the register: plain た is the casual past. In polite speech you use the 〜ました form at the sentence end — but even then, た reappears inside the sentence (past relative clauses, 〜たら, 〜たことがあります), because embedded clauses always take the plain form.
Common mistakes
❌ 昨日、面白い本を読んた。
Wrong — the ぬ・ぶ・む group is voiced: 読む → 読んだ, never ×読んた. The voicing carries over from the te-form 読んで.
✅ 昨日、面白い本を読んだ。
kinō, omoshiroi hon o yonda
I read an interesting book yesterday.
❌ 海で泳いた。
Wrong — -ぐ is voiced too: 泳ぐ → 泳いだ, matching the te-form 泳いで.
✅ 海で泳いだ。
umi de oyoida
I swam in the sea.
❌ 先生とゆっくり話った。
Wrong — -す never doubles to った; it takes した (no 音便): 話す → 話した.
✅ 先生とゆっくり話した。
sensei to yukkuri hanashita
I had a good, unhurried talk with my teacher.
❌ 図書館に行いた。
Wrong — 行く is the exception; its past is 行った, not the regular ×行いた you'd expect from a -く verb.
✅ 図書館に行った。
toshokan ni itta
I went to the library.
❌ 手紙を書きた。
Wrong — the past is built off the te-form (書いて → 書いた), not off the ます-stem 書き.
✅ 手紙を書いた。
tegami o kaita
I wrote a letter.
Key takeaways
- The past た-form = the te-form with て → た, で → だ. Learn one and you have the other.
- Rows group by 音便 exactly like the te-form: う・つ・る → った, ぬ・ぶ・む → んだ, く → いた, ぐ → いだ, す → した, 一段 → た.
- The voicing carries over: 読んだ・泳いだ・遊んだ・死んだ, never ×読んた／×泳いた.
- Irregulars する → した, 来る → 来た（きた）; the one 音便 exception is 行く → 行った.
- た is the base for 〜たら, 〜たり, 〜たことがある, and past relative clauses — so it is worth mastering beyond the plain past.
Now practice Japanese
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Japanese→Related Topics
- te/ta Sound-Change (音便) Master ChartN4 — The definitive euphonic-change reference: every verb ending mapped to its te and た form, with the three 音便 types, the voicing rule, and the single 行く exception.
- Plain Form (辞書形/ない/た): TableN5 — The four plain (常体) verb cells — dictionary, negative ない, past た, past-negative なかった — across every class, with each mapped to its polite equivalent.
- ます-Form: Conjugation TableN5 — The complete polite ます-family across every verb class — present, negative, past, past-negative, and volitional — all built on the い-row 連用形 stem.
- The て/た Parallel: One Machinery, Two FormsN4 — The plain past た-form uses exactly the same sound-changes as the て-form — learn one and you get the other for free, along with the たら conditional and たり listing.
- 書く: Full 五段 -く ParadigmN5 — The complete reference paradigm for a godan verb ending in -く, using 書く (to write): the い-音便 te-form 書いて and the one famous exception, 行く → 行って.