adverb modifies a verb, adjective, or other adverb, typically indicating the manner in which something is done
preposition a word that shows the relationship between a noun (or pronoun) and other words in a sentence
The candidate addressed the controversial topic in passing during the debate.
The lawyer brought up a crucial piece of evidence in passing during the cross-examination.
In passing, the CEO hinted at a potential merger with a competitor.
In passing, the professor mentioned a new research study that sparked the students' interest.
During the post-game interview, the coach made a brief comment in passing about the team's upcoming training schedule.
The ethnographer made a casual observation in passing about the local customs.
The artist mentioned a new technique in passing during the gallery opening.
In passing, the author mentioned a key point that tied the whole argument together.
During the therapy session, the patient briefly mentioned her childhood trauma in passing.