Here's why:
* Question words: These are the most common "starters": *who, what, when, where, why, how*, and their variations (*which, whose, whom*).
* Other interrogative words: While not as common, words like *whether, if, is, are, do, does, did, have, has, had* can also initiate a question.
* Phrases: Questions can begin with phrases like *can you, would you, have you, do you, is it, are they*.
Here's a better way to think about it:
A question typically needs a question mark at the end, and it should use an inverted word order, meaning the verb usually comes before the subject.
For example:
* Correct: "Where is the library?"
* Incorrect: "The library is where?"
To summarize:
* There's no strict list of words that *must* start a question.
* Focus on the structure of the question: a question mark at the end, and the verb usually preceding the subject.