Why do Americans say listen up and not listen?
All languages change over time. In the evolution of American English, phrasal verbs seem to be becoming more common. A phrasal verb is a combinaton of a verb and a preposition or in some instances a noun and preposition as in “to man up” like “You need to man up and take responsibility for your mistakes” etc. I am American and I still do not say “listen up.” I would say “Listen everyone” or “Listen everybody” instead. Of course, I grew up in an era (1950’s, 60’s) when parents and teachers strongly discouraged us from using what were considered lower-class forms. We were even told that using them would affect our ability to get good jobs when we grew up. However, this is a little less true today because the country has changed since then.
