Wǒ jīnnián 21 nián.
False:我今年21年。
Wǒ jīnnián 21 suì.
True:我今年21岁。
英语year可以表示时间(in the year 1985),也可以表示年龄(He is 20 years old)。汉语的“年”则只表示时间,应将受英语影响的“年”改成汉语表示年龄的“岁”。
"Year" in English indicates time(in the year 1985)as well as age(He is twenty years old). But 年 in Chinese only refers to time. 年, the use of which here is the consequence of interference of English language, should be changed into 岁 meaning age.