The Mandarin Chinese particle de (?) is most commonly used as a possessive modifier. It can be used between two nouns to indicate a relationship of possessor / possession.

For example:

Wo de péngyou.
My friend.
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Notice that de is used after the first (pro)noun. This gives us the following possessive pronouns:

Mine – wo de
Yours – ni de
His – ta de
Hers – ta de
Theirs – tamen de
Ours – women de

The de particle can be used for any possessive noun or pronoun, such as “Miss Chen’s pen” (Chén xiaojie de bi), or “American schools” (Meiguó de xuéxiào).

Descriptors

The de particle can also used in describing objects or people. “Big chair” is dà de yizi. In this usage de follows the adjective.

Examples:

lánsè de yifu
blue clothing
?????

yìdàlì de che zi
Italian car
??????

Emphasis

The de particle is sometimes used for emphasis or affirmation.

Wo huì qù de!
I am going!
????!

Shàngkè, yào zhuanxin de.
When you are in class, you have to concentrate.
??, ????｡