Lesson 8: The verb strikes back: the past tense

You form the past tense of a verb by attaching た or だ to the right "stem". Stems are basically the shortest verb forms you can write. You attach the right stuff to the end of the right stem when you want to make complex conjugations.

We're introducing stems now because the past tense of five-form verbs uses irregular stems.

90% of the time, you only use three stems. Here's an example:

殺す　死ぬ

殺さ　死な

殺し　死に/死ん

Here's an example of these stems in use:

殺す

"he kills"

殺さない

"he doesn't kill"

殺した

"he killed"

That's right. Basic stuff like tense and negation uses only three stems. There are more stems, but they show up less often. We'll cover them later.

With that out of the way, we can introduce the past tense properly. We've seen the past tense forms of だ and です already, which are だった and でした. We also saw 殺した in the stem example above.

You'd be right to assume that the た is what makes it the past tense. The hard part, and the reason for the delay, is that the stem for the past tense of five-form verbs isn't as regular as the stem for the negative form. It depends on the exact original syllable ending. Here are all possibilities:

切る殺す死ぬ選ぶ読む買う問う動く急ぐ持つ
切った殺した死んだ選んだ読んだ買った問うた動いた急いだ持った

Don't memorize this table. There's a rule for this, it's just irregular. Replace the "u" vowel with an "i" vowel, so you get like 切り, 死に, etc. Then attach the た, but slur it. The slurring is what makes it irregular. In particular, notice 死んだ and 急いだ.

Japanese speakers don't go through this process whenever they conjugate something. This process is like trivia to them. The "slurring" is a historic thing, and the slurred version is just what the form is now. At the very least, if you do a little reading and listening in japanese, you will be able to recognize the past tense at a glance. Exposure is more powerful than memorization.

The past tense of one-form verbs is easy. Replace the る with a た.

見る　見た

食べる　食べた

We will learn another use of this stem, one where it's not slurred with five-form verbs, in Lesson 12.

Conjugation is more complicated than this, but take this one step at a time.

問う, 請う, and 恋う have irregular past conjugations among う-final five-form verbs. They might not be particularly common verbs, but they use a う stem for the past tense instead of the lengthened consonant. This is an example of the slurring being irregular.