Japanese Past Tense: Polite and Plain Forms Explained
The Japanese past tense is simpler than it looks. Polite verbs change ます (masu) to ました (mashita), and the negative ません (masen) becomes ませんでした (masen deshita). In casual speech you use the plain past, called the ta form, and its negative ends in なかった (nakatta). There are no endings for I, you or they to learn, so one form works for everyone.
How do you form the polite past tense in Japanese?
Start here. Polite forms are what you use with people you do not know well, and they are the easiest to build. Take the ます form of any verb and change the ending.
- たべます (tabemasu, I eat) becomes たべました (tabemashita, I ate).
- たべません (tabemasen, I do not eat) becomes たべませんでした (tabemasen deshita, I did not eat).
The same rule works for every verb, including the irregular ones. します (shimasu, I do) becomes しました (shimashita), and きます (kimasu, I come) becomes きました (kimashita).
です (desu, is) has its own past: でした (deshita, was). Its negative is じゃありませんでした (ja arimasen deshita, was not).
きのう すしを たべました。
Kinō sushi o tabemashita.
I ate sushi yesterday.
がくせいでした。
Gakusei deshita.
I was a student.
How does the plain past tense (ta form) work?
The plain past is used with friends and family, and inside longer sentences. It follows the same sound changes as the te form. You simply finish with た (ta) or だ (da) instead of て (te) or で (de). How it changes depends on the verb group.
Ru verbs are the easy group. Drop る (ru) and add た (ta): たべる (taberu, to eat) becomes たべた (tabeta, ate), and みる (miru, to see) becomes みた (mita, saw).
U verbs change according to their last sound.
| Ending | Dictionary form | Plain past |
|---|---|---|
| く | かく (kaku, to write) | かいた (kaita) |
| ぐ | およぐ (oyogu, to swim) | およいだ (oyoida) |
| う, つ, る | まつ (matsu, to wait) | まった (matta) |
| む, ぶ, ぬ | のむ (nomu, to drink) | のんだ (nonda) |
| す | はなす (hanasu, to speak) | はなした (hanashita) |
A few more from the same rows: かう (kau, to buy) becomes かった (katta), and あそぶ (asobu, to play) becomes あそんだ (asonda). Watch out for いく (iku, to go). It ends in く, but its past is いった (itta), not いいた.
Irregular verbs are just two: する (suru, to do) becomes した (shita), and くる (kuru, to come) becomes きた (kita).
How do you make the plain past negative?
Take the plain negative, which ends in ない (nai), and change ない to なかった (nakatta).
- たべない (tabenai, do not eat) becomes たべなかった (tabenakatta, did not eat).
- のまない (nomanai, do not drink) becomes のまなかった (nomanakatta, did not drink).
- しない (shinai) becomes しなかった (shinakatta), and こない (konai) becomes こなかった (konakatta).
Adjectives have a past too. い adjectives change い to かった, as in たかかった (takakatta, was expensive), and な adjectives use でした (deshita). Our guide to i adjectives vs na adjectives covers both.
What does the full past tense chart look like?
Here are the four past forms of one ru verb and one u verb side by side.
| Form | たべる (taberu, to eat) | のむ (nomu, to drink) |
|---|---|---|
| Polite positive | たべました (tabemashita) | のみました (nomimashita) |
| Polite negative | たべませんでした (tabemasen deshita) | のみませんでした (nomimasen deshita) |
| Plain positive | たべた (tabeta) | のんだ (nonda) |
| Plain negative | たべなかった (tabenakatta) | のまなかった (nomanakatta) |
If you are just starting, use the polite forms when you speak, and learn to recognise the plain forms when you hear them. Most of these verbs appear on JLPT N5 word lists, the easiest level, as our JLPT N5 vocabulary list shows.
How LanguaCards helps
Past tense endings stick best when you know the verbs well. In LanguaCards, every Japanese card has audio and romaji, so you hear each verb as you learn it. Topic packs give you everyday words to start with, and you can add the verbs you use most to a pack of your own.