Breakdown of Der Professor und der Student diskutieren. Ersterer spricht, Letzterer hört zu.
und
and
sprechen
to speak
zuhören
to listen (to someone/something)
diskutieren
to discuss
Questions & Answers about Der Professor und der Student diskutieren. Ersterer spricht, Letzterer hört zu.
Why do Ersterer and Letzterer both end in "-er" here?
They refer back to der Professor and der Student, which are both masculine nouns. Since they act as the subjects of the second sentence (nominative case) and are used without an article, they take the strong masculine ending -er.
Could I say der Erstere and der Letztere to match the English "the former" and "the latter"?
Yes, you can! You can use them with or without the definite article. Just remember that if you add der, the ending changes to the weak adjective ending -e, making them der Erstere and der Letztere.
Why are Ersterer and Letzterer capitalized?
Because they are acting as nouns. They are technically adjectives (first and last) that have been nominalized, meaning they stand alone to replace the nouns Professor and Student. In German, nominalized adjectives are always capitalized.
Is it grammatically correct to link the two halves of the second sentence with just a comma?
Yes, this is very common in German. While English typically requires a semicolon or a conjunction (like "while" or "and") to join two independent clauses, German frequently uses a comma to connect short, highly contrasted main clauses like Ersterer spricht, Letzterer hört zu.