Questions & Answers about Ich frage die Journalistin, was das Thema ist.
Why is ist at the very end of the sentence?
This is an indirect question. When a question word like was connects two parts of a sentence, it creates a subordinate clause. In German subordinate clauses, the conjugated verb (here, ist) is always pushed to the very end.
Is die Journalistin in the accusative case here?
Yes. The verb fragen (to ask) needs a direct object, which takes the accusative case. Because Journalistin (female journalist) is a feminine noun, the accusative article is die, which happens to look exactly like the basic nominative case.
Do I always need a comma before the question word was?
Yes. In English, we write 'I ask her what the topic is' without a comma. But German punctuation rules are stricter: you must always use a comma to separate the main clause (Ich frage die Journalistin) from the indirect question (was das Thema ist).
Why is Thema a neuter noun (das) if it ends in an 'a'?
While it is true that most native German words ending in 'a' or 'e' are feminine, das Thema (the topic) is a loanword from Greek. Many of these Greek words ending in -ma are neuter, such as das Klima (the climate) or das Drama (the drama).