在 + Noun + 上
The postposition 上 (shàng) indicates a position on the surface of or on top of something. It typically appears after a noun to form a location phrase, often paired with 在 to indicate where something is placed or situated. It is one of the most frequently used directional words in Chinese.
书在桌子上,你自己去拿吧。
shū zài zhuōzi shàng, nǐ zìjǐ qù ná ba.
The book is on the table — go get it yourself.
墙上挂着一幅很漂亮的画。
qiáng shàng guà zhe yì fú hěn piàoliang de huà.
A very beautiful painting is hanging on the wall.
猫喜欢趴在沙发上睡觉。
māo xǐhuān pā zài shāfā shàng shuìjiào.
Cats like to lie on the sofa and sleep.