I'm trying to put together a chart for myself, to learn the rules for verb conjugation. However, I'm confused at the "Imperfective" and "Perfective" verb conjugations - aren't they just informal versions of the "Masu" verb forms? To my understanding, the "masu" verb forms are polite ways to say something is either happening or will happen - just like the "Imperfective" verbs(Which appear to just be the dictionary forms?)

  • For example, "Tabemasu" vs "Taberu" - both mean that something is either being eaten or will be eaten.

Likewise, the "mashita" verb forms indicate that something has already happened - just like the "perfective" verb forms.

  • For example, "Tabemashita" vs "Tabeta" - both mean something has been eaten?

1 Answer 1


For example, "Tabemashita" vs "Tabeta" - both mean something has been eaten?

Yes. They do not differ in meaning, only usage.

Keep in mind there are some times when it's inappropriate to use たべた (tabeta); typically these are in more formal (or less familiar) situations. Conversely, there are times when it is inappropriate to use たべました (tabemashita); typically these are in more familiar situations, among family or friends, or in certain grammatical constructs. (This would also be the case for taberu and tabemasu, and so on.)

If you want to read further on the topic, there's quite a bit of discussion and help surrounding these constructs.

  • So, the "perfective" and "imperfective" verb forms are just the informal variants, then? Same meaning, different usages? It is very confusing why the sites list them as "perfective"/"imperfective" without stating this. Commented Mar 10, 2015 at 20:42
  • Ah--I think I see where your confusion is. Imperfective is actually present tense. Both taberu and tabemasu are the imperfective tense. Perfective is the past tense, like tabeta and tabemashita.
    – Cat
    Commented Mar 10, 2015 at 20:45
  • I see! So "Perfective" vs "Imperfective" isn't just less formal variants of verbs, but rather the tenses used? Commented Mar 10, 2015 at 20:48
  • 1
    That's correct!
    – Cat
    Commented Mar 10, 2015 at 20:48
  • @DanielMartin Yeah, or more precisely, aspects. But some people consider them tenses instead, and these people refer to them as "past" and "nonpast", so you'll see those names too.
    – user1478
    Commented Mar 11, 2015 at 0:50

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