The word "er" is often used as a suffix in English, typically to form nouns that describe a person who performs a specific action or has a certain role. It can denote someone who does something, like a "teacher" (someone who teaches) or "runner" (someone who runs). It can also be used informally as an interjection expressing hesitation, uncertainty, or thought.
The suffix "er" originates from Old English, where it was used to form nouns indicating a person engaged in a specific activity. It comes from the Proto-Germanic *-ira, which also served a similar function in other Germanic languages.
The interjection use can be exemplified as follows: 1. Hesitation: "I was, er, thinking about going to the movies tonight."