每天 (měi tiān) literally combines 每 (měi), meaning 'each' or 'every', and 天 (tiān), meaning 'day'. Together, it functions as an adverb meaning 'every day' — indicating something that occurs regularly, without exception, on all days. It is commonly placed before a verb or verb phrase to express habitual or repeated action, such as studying, exercising, or eating breakfast.

This word is fundamental in describing routines, schedules, and consistent habits. Unlike time nouns like 今天 (today) or 明天 (tomorrow), 每天 is not a specific point in time but a frequency marker. It’s neutral in register — appropriate in both spoken and written Chinese — and frequently appears in daily conversations, health advice, language-learning goals, and work-related planning. While it may appear in noun-like contexts (e.g., 每天的练习), its core grammatical role remains adverbial when modifying verbs.