Introduction to Past Tense
The past tense in Japanese is used to describe actions or states that have already happened or were true in the past. Unlike English, Japanese verbs conjugate to express past tense rather than using auxiliary verbs like "did" or "was."
In Japanese, the past tense is formed primarily by changing the verb ending. There are two main verb groups (ru-verbs and u-verbs) and a few irregular verbs, each with their own conjugation patterns.
食べた
tabeta
ate (past tense of "eat")
行った
itta
went (past tense of "go")
Past Tense of Ru-Verbs
Ru-verbs (also called ichidan verbs) end with 〜る in their dictionary form. To form the past tense, simply replace る with た.
| Dictionary Form | Past Tense |
|---|---|
| 食べる (taberu) | 食べた (tabeta) |
| 見る (miru) | 見た (mita) |
映画を見た。
Eiga o mita.
I watched a movie.
ご飯を食べた。
Gohan o tabeta.
I ate a meal.
Past Tense of U-Verbs
U-verbs (godan verbs) end with a variety of 〜う、〜く、〜ぐ、〜す、〜つ、〜ぬ、〜ぶ、〜む、〜る. Their past tense conjugation depends on the final syllable of the verb stem. The ending changes to either った, いた, or いだ.
| Verb Ending | Past Tense Ending | Example | Past Form |
|---|---|---|---|
| う、つ、る | った | 買う (kau) | 買った (katta) |
| む、ぶ、ぬ | んだ | 読む (yomu) | 読んだ (yonda) |
| く | いた | 書く (kaku) | 書いた (kaita) |
| ぐ | いだ | 泳ぐ (oyogu) | 泳いだ (oyoida) |
| す | した | 話す (hanasu) | 話した (hanashita) |
手紙を書いた。
Tegami o kaita.
I wrote a letter.
友達と話した。
Tomodachi to hanashita.
I talked with a friend.
川で泳いだ。
Kawa de oyoida.
I swam in the river.
Past Tense of Irregular Verbs
There are two main irregular verbs in Japanese: する (to do) and 来る (くる, to come). Their past tense forms are unique and must be memorized.
| Verb | Past Tense |
|---|---|
| する (suru) | した (shita) |
| 来る (くる, kuru) | 来た (きた, kita) |
宿題をした。
Shukudai o shita.
I did my homework.
彼は学校に来た。
Kare wa gakkou ni kita.
He came to school.
Negative Past Tense
To form the negative past tense, first conjugate the verb into its negative present form, then change ない to なかった. This applies to all verb groups.
For example, 食べる (to eat) becomes 食べない in the negative present, and 食べなかった in the negative past.
昨日はご飯を食べなかった。
Kinou wa gohan o tabenakatta.
I did not eat rice yesterday.
映画を見なかった。
Eiga o minakatta.
I did not watch the movie.
Polite Past Tense
To make the past tense polite, use the 〜ました ending, which comes from adding 〜ます to the past tense stem.
For ru-verbs and u-verbs, conjugate to the 〜ます stem, then add ました.
| Dictionary Form | Polite Past |
|---|---|
| 食べる (taberu) | 食べました (tabemashita) |
| 行く (iku) | 行きました (ikimashita) |
昨日、友達と話しました。
Kinou, tomodachi to hanashimashita.
I talked with my friend yesterday.
朝ご飯を食べました。
Asagohan o tabemashita.
I ate breakfast.
Practice Examples
Try to identify the verb type and conjugate the verbs into past tense in these sentences:
昨日、図書館で本を読んだ。
Kinou, toshokan de hon o yonda.
I read a book at the library yesterday.
彼女は手紙を書いた。
Kanojo wa tegami o kaita.
She wrote a letter.
試験をしなかった。
Shiken o shinakatta.
I did not take the exam.
父は会社に来た。
Chichi wa kaisha ni kita.
My father came to the office.
Tips for Remembering Rules
1. Remember that ru-verbs are the easiest to conjugate: just replace る with た for past tense.
2. For u-verbs, focus on the last syllable of the dictionary form to decide the correct past tense ending (った, いた, いだ, etc.).
3. The irregular verbs する and 来る are very common, so memorize their past forms (した and 来た).
4. Negative past tense always ends with なかった. Just change ない to なかった after making the verb negative.
5. Practice with polite forms by using ました endings, which are consistent across all verbs.
6. Listening and reading real Japanese examples will help internalize these patterns quickly.