Translation guide
The English phrase "first part" can refer to the initial section of something, the opening segment of a performance, or the first installment of a series. Japanese uses different words depending on what is being divided.
first part (general)
Most common for 'first half' or 'earlier part'.
first part (of a series)
Use for Part 1 of a structured work.
Referring to the beginning portion of a book, movie, speech, event, etc.
The first half or earlier part of something. Commonly used for time periods, events, or structured content.
The first part of the movie was a little boring.
The first part of the match was evenly matched.
Literally 'the initial part'. A straightforward, neutral phrase that works in many contexts.
The very beginning or opening of a speech, story, or written work. More formal/literary.
The opening stage or early phase, often used in games, competitions, or narratives.
Referring to Part 1 of a multi-part work, such as a book series, film series, or serialized content.
Standard way to say 'Part 1' for structured works. Can be used for books, movies, etc.
The first part of this series is very interesting.
The first part of a two-part work. Often used for movies or stories split into two.
The first volume of a multi-volume book set. Specifically for physical volumes.
The first act or opening number of a show, concert, or theatrical performance.
前半 (ぜんはん) implies a roughly equal division into halves, while 最初の部分 (さいしょのぶぶん) simply means the beginning portion without implying a 50/50 split. Use 前半 for halves of time or content, and 最初の部分 for the opening segment of any length.
The direct translation 「最初の部分」 is grammatically correct but can sound unnatural in contexts where a specific term like 前半 or 第1部 is expected. Pay attention to whether the 'first part' is a half, an installment, or just the beginning.
I rewrote the first part of the report.
スピーチの冒頭で感謝の言葉を述べた。
In the first part of the speech, I expressed my gratitude.
ゲームの序盤で大きなミスをした。
I made a big mistake in the first part of the game.
その映画は前編と後編に分かれている。
The movie is split into a first part and a second part.
この小説の上巻を読み終えた。
I finished reading the first part of this novel.
オペラの序曲が始まった。
The first part of the opera, the overture, began.