'归功于' is a formal, written verb phrase meaning 'to attribute (credit, success, or achievement) to someone or something.' Literally, 归 means 'to return' or 'to ascribe,' 功 means 'merit,' 'achievement,' or 'contribution,' and 于 is a preposition meaning 'to' or 'toward.' Together, the phrase conveys the idea of assigning credit or causation — not just acknowledging influence, but explicitly recognizing the source of a positive outcome. It is commonly used in academic writing, news reports, speeches, and formal explanations.

This expression carries a tone of respect and gratitude; it’s rarely used for negative outcomes (for which you’d use 归咎于 instead). It often appears with subjects like achievements, progress, improvements, or breakthroughs, and its object is typically a person, group, factor, or condition that enabled the result. Because of its formal register, it’s uncommon in casual conversation among friends or family.