1To divide, separate, or partition something (space, time, text, etc.) into parts.
部屋をカーテンで区切って、二つの空間に分けた。
We divided the room into two spaces with a curtain.
プロジェクトをいくつかの段階に区切って進める。
We proceed with the project by dividing it into several stages.
一年を四半期ごとに区切って業績を管理する。
We manage performance by dividing the year into quarters.
2To punctuate a sentence, or insert pauses when speaking, to mark off phrases clearly.
単語を一つずつ区切ってはっきり発音した。
I pronounced each word clearly, separating them one by one.
長い一文をどこで区切るか迷ってしまう。
I can't decide where to break up this long sentence.