的 — saying whose something is

Whose book is this?

• A book is lying on the classroom desk. Your classmate asks whose it is. It is yours.
• this这zhèis是shìI, me我wǒ(modifier / structural particle)的debook书shū。 Zhè shì wǒ de shū. — "This is my book."

Person + (modifier / structural particle)的de + thing

• (modifier / structural particle)的de (de) shows who something belongs to: I, me我wǒ(modifier / structural particle)的debook书shū, my book; teacher老师lǎoshī(modifier / structural particle)的detelephone电话diàn huà, the teacher's phone.
• The owner comes first, then (modifier / structural particle)的de, then the thing. This is the opposite of English “of”: teacher老师lǎoshī(modifier / structural particle)的debook书shū = the book of the teacher.

this这zhèis是shìmy我wǒ的debook书shū。

Family and close people: (modifier / structural particle)的de is often dropped

• For family and close relationships, (modifier / structural particle)的de is usually left out: I, me我wǒmum妈妈māma wǒ māma, my mum; I, me我wǒfriend朋友péng yǒu, my friend; we / us我们wǒ menschool学校xué xiào, our school.
• For things, keep (modifier / structural particle)的de: I, me我wǒ(modifier / structural particle)的decup杯子bēi zi, my cup.

my我wǒmum妈妈māmais是shìteacher老师lǎoshī。

Asking whose: who谁shéi(modifier / structural particle)的de

• this这zhèis是shìwho谁shéi(modifier / structural particle)的de？ Zhè shì shéi de? — "Whose is this?" Answer: is是shìI, me我wǒ(modifier / structural particle)的de, it's mine.
• (modifier / structural particle)的de can end the answer when the thing is clear: this这zhèroot本běnbook书shūis是shìI, me我wǒ(modifier / structural particle)的de, this book is mine.

Watch out

Recap