When communicating in Chinese you may often make mistakes using Chinese grammar like:

False:

    我今年21年。

    Wǒ jīnnián 21 nián.

True:

    我今年21岁。

    Wǒ jīnnián 21 suì.

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.