In the process of learning Japanese, I've been doing some grammar analysis on sentence structure (across languages), Eg. subject, object, etc. I've come across something I haven't heard of before: the "topic" of the sentence.
Take this sentence: "Regarding coffee, arabica is smooth." "Arabica" is the subject, and in Japanese, "coffee" would be called the topic.
I can't find anything on the term "topic" as a classification of a part of a sentence in English. How is this defined in English?