乎

As a modal particle: marks questions (genuine or rhetorical), exclamation, wonder, and doubt, or serves as a "softener" to leave the tone of a sentence open.

As a preposition: in, at, from, to, with.

Final position: functions as a modal particle that modulates the mood of the statement without altering propositional content.

Medial position: functions as a preposition indicating location, origin, direction, or the object of an action.

Compared to 歟 (yū): While both are final interrogatives, 歟 is often associated with irony or skepticism; 乎 is more general. This distinction can be stylistic and varies by period.

In early texts, frequently interchangeable with 于 and 於 when functioning as a preposition.

If the syntax of a passage fails when treating 乎 as a final question marker, test it as a preposition (read as //yú//).