抄録
This study analyzes the usages of "ru"(non-past) and "ta"(past) at the end of sentences in Japanese by observing native speaker's utterances when they are talking about the past events. Although "ta" is the standard past tense ending of a sentence, this study found that native speakers use "ru" for remarking on the unknown events that happened in the past but are introduced newly by their partner. However, the main difference in the use of "ta" and "ru" in the hurry of speech is only in special cases when, in the text of the past event, they can omit verbs with "ta" at the end of the sentence, but never omit those with "ru".
