岁
year of age; years old
suì
What does 岁 mean?
岁 (suì) is the measure word for a person's age in years. The pattern is simply NUMBER + 岁 — no extra verb required. 我二十岁 literally means 'I twenty years-of-age,' which is the complete and natural sentence for 'I am twenty years old.' Note that Chinese does NOT use 是 (to be) here — 我是二十岁 is grammatically wrong; the number-plus-岁 chunk acts as its own predicate. To ASK age, the question word depends on the listener: 你几岁？ for small children (expecting a single digit), 你多大？ for everyone else, 您多大年纪？ for elders (polite). 岁 only counts years of human / pet life; for object years use 年.
Character breakdown
year of age (the 山 'mountain' top is phonetic-historical, not literal)
Memory hook: 岁 has 山 on top — each year is another mountain you climb in life.
Example sentences
我二十岁。
Wǒ èrshí suì.
I'm twenty years old.
spoken
他的女儿五岁。
Tā de nǚ'ér wǔ suì.
His daughter is five years old.
neutral
你几岁了？
Nǐ jǐ suì le?
How old are you? (asking a small child)
spoken
我妈妈五十岁。
Wǒ māma wǔshí suì.
My mom is fifty years old.
spoken
Common phrases with 岁
Synonyms
年 is the general word for 'year' — calendar years, durations, anniversaries. 岁 is specifically a person's age count. 三年 = three years (duration); 三岁 = three years old.
Don't confuse 岁 with
年 = a year as a unit of time. 岁 = a year of someone's age. '一年前 (one year ago)' uses 年; '十岁 (ten years old)' uses 岁.
Same pronunciation but 碎 means 'broken / shattered.' Different character with the 石 stone radical.