甚麼 (shénme) is the standard written and spoken Mandarin word for 'what' — a fundamental interrogative pronoun used to ask about identity, nature, content, or purpose. The first character 甚 (shèn) originally meant 'very' or 'extremely' in classical Chinese, but in this compound it functions as a phonetic element; the second character 麼 (me) is a grammatical particle that turns statements into questions when attached to question words. Together, they form an inseparable unit meaning 'what' — never segmented or altered in speech.

This word appears at the beginning or middle of questions, often followed by verbs (e.g., 甚麼事？), nouns (e.g., 甚麼動物？), or adjectives (e.g., 甚麼顏色？). It’s neutral in register — appropriate in casual conversation, classroom settings, and formal writing. Unlike English 'what', 甚麼 never stands alone as a complete sentence; it always requires a verb or noun to complete the question’s meaning.