How to Conjugate Long-Term Past Tense in Japanese With Ru-Verbs, U-Verbs and Irregular Verbs

Describing Things in the Past in Japanese

We have already learned how to form Japanese verbs in the long-form present tense, so let’s go over how to conjugate them in the past tense. Like in English, the past tense verb form is used to describe things that have already happened. In Japanese, the rules for long-form past tense follows the same rules as long-form present tense.

Ru-verbs

Reviewing -ru verbs quickly; theる(ru) is removed to get the stem of verb, which is used to conjugate. Let’s use the same -ru verb we did in the present tense lesson: たべる(taberu) “to eat”:

Dictionary Form たべる(taberu)

Stem たべ(tabe)

Now in affirmative present form, we use the ending -ます (masu); that ending changes to -ました (mashita) for the affirmative past form:

Past, Affirmative たべました (tabemashita)

The same works for the negative form: -ません (masen) from the present form becomes -ませんでした (masendeshita) for the past form:

Past, Negative たべませんでした (tabemasendeshita)

U-verbs

To form the past tense with -u verbs, we follow the same rules as we did for present tense, and then use the past tense endings -ました (mashita) and -ませんでした (masendeshita), just like for -ru verbs. Let’s go over the two examples we had in the previous lessons: いく(iku) “to go” and かえる(kaeru) “to return” :

Dictionary Formいく(iku)

Stem いき(iki)

Present, Affirmative いきま****した(ikimashita) ← notice the change in the ending

Present, Negative いきません****でした(ikimasendeshita) ← notice the change in the ending

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Dictionary Form かえる(kaeru)

Stemかえり(kaeri)

Present, Affirmative かえりま****した(kaerimashita) ← notice the change in the ending

Present, Negative かえりません****でした(kaerimasendeshita) ← notice the change in the ending

Irregular Verbs

The two irregular verbs we learned before, する(suru) “to do” and くる(kuru) “to come,” follow the same conjugation rules as in present tense, except for a change in the endings:

Dictionary Form す****る (suru)

Stemし(shi)

Present, Affirmativeしま****した(shimashita) ← notice the change in the ending

Present, Negativeしません****でした(shimasendeshita)← notice the change in the ending

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Dictionary Form くる(kuru)

Stem き(ki)

Present, Affirmative きま****した(kimashita) ← notice the change in the ending

Present, Negativeきません****でした(kimasendeshita) ← notice the change in the ending

Additional Endings

We also learned how to form basic sentences, and use the word です (desu) when there is not another verb. We also learned the negative equivalent, じゃありません(ja arimasen). Both have past tense forms:

です → でした

じゃありません → じゃありませんでした

Notice the endings for these words are similar to the verb endings.

References

• Banno, E., Ohno, Y., Sakane, Y. and Shinagawa, C. An Integrated Course in Elementary Japanese. The Japan Times, 1999