ukkari kaigi no jikan o machigaete shimaimashita.

direct object particle

Breakdown of ukkari kaigi no jikan o machigaete shimaimashita.

• の: possessive case particle
• 時間じかん: time
• 〜て: connective form

Questions & Answers about ukkari kaigi no jikan o machigaete shimaimashita.

What does the word うっかり do here? Is it an adverb, and does it need any particle?

うっかり is an adverb meaning “carelessly,” “absent‑mindedly,” or “by oversight.” It directly modifies the action and does not take a particle. You can put it at the start or right before the verb phrase:

• うっかり会議の時間を間違えてしまいました。 You’ll also see うっかりして when it’s linked to the following clause:
• うっかりして鍵を忘れました。

Why is の used between 会議 and 時間?

の marks an attributive/possessive relationship: 会議の時間 = “the time of the meeting.” It’s like “meeting’s time.” This structure is very common: 会社の住所 (company’s address), 日本の文化 (Japan’s culture), etc.

Why is を used after 時間? Could another particle be used?

間違える takes a direct object with を. The pattern is “X を 間違える” = “to get X wrong.” Here, 時間 (the meeting time) is what was gotten wrong, so 時間を is required. Using に would change the meaning to “at the time of the meeting,” which isn’t the point here.

What nuance does the てしまいました add?

〜てしまいました signals completion and often implies an unintended result or regret. So 間違えました is neutral “(I) made a mistake,” while 間違えてしまいました adds “I (regrettably/accidentally) made a mistake.” Context decides whether the nuance is just completion or also “oops/regret.”