Lesson 6: The Past Tenses

In this lesson, I will teach you how to conjugate verbs into both the polite and the plain past tense. I will first teach the polite past tense because conjugating verbs into it is easier than conjugating verbs into the plain past tense.

Conjugating verbs into the polite past tense is the same for all the groups of verbs. You first conjugate the verb into its ます-stem then add ました to the end of the verb, i.e. あい→あいました, たべ→たべました, and きき→ききました.

Conjugating Group 1 verbs into the plain past tense is a bit harder than conjugating them into the polite past tense since there's more to memorize. The basic steps are the same but there are minor differences depending on which kana ends the verb. If the verb ends in う, つ, or る, you replace ending kana with った, i.e. あう→あった, たつ→たった, and うる→うった. If the ending kana is く, you replace the kana with いた, i.e. きく→きいた. If the ending kana is ぐ, you replace it with いだ, i.e. およぐ→およいだ. If the ending kana is す, you replace it with した, i.e. ころす→ころした. If the verb ends in ぬ, ぶ, or む, you replace the ending kana with んだ, i.e. しぬ→しんだ, よぶ→よんだ , and ぬすむ→ぬすんだ. While that covers all of the normal Group 1 verbs, it does not cover the Group 1 verb 行く (いく） since it's slightly irregular. To conjugate 行く, you replace the く with った, i.e. 行く（いく）→行った（いった）.

Conjugating Group 2 verbs and the irregular verbs into the plain past tense is far easier than conjugating Group 1 verbs into the plain past tense. You just take the ます-stem of the verb and add た to the end of it, i.e. たべ→たべた, たり→たりた , い→いた , しー＞した , and 来（き）→来た（きた）, to conjugate a Group 2 verb or an irregular verb into the plain past tense.

With this lesson and lesson three, you now know all of the basic conjugations of Japanese except for the polite and plain tenses of both the negative present tense and the negative past tense, so you are halfway done learning the basic conjugations of Japanese.

John