Here's why:
* Word order: German uses word order to indicate a question. The verb is often moved to the beginning of the sentence. For example:
* Statement: "Der Mann liest das Buch." (The man reads the book.)
* Question: "Liest der Mann das Buch?" (Does the man read the book?)
* Interrogative words: Words like "wer" (who), "was" (what), "wann" (when), "wo" (where), etc., are used to ask specific questions. They *can* be included in a question but aren't always necessary.
* Question with interrogative word: "Wer liest das Buch?" (Who reads the book?)
* Question without interrogative word: "Liest er das Buch?" (Does he read the book?)
In summary: While interrogative words are useful for asking specific questions in German, you can still form a question simply by changing the word order.