Interrogative pronouns are the pronouns you use to ask questions. The placement of question words is actually a little easier than it is in English, because Chinese doesn't move them around like English does. Instead, the question words stay "in-situ," that is, where the answer to the question will go.
These are the main interrogative pronouns, often called "WH-words" in English because most of them start with those letters.
The words to ask about quantity are 多少 and 几. 多少 is a versatile interrogative pronoun and can cover any number, but 几 is generally used for numbers 1 - 9. Additionally, 几 requires a measure word, but 多少 doesn't need one. Interrogative pronouns can act as indefinite references meaning "anything," "anyone," "something" or "someone." e.g. 谁都喜欢中国菜.