买 + (了) + Object
The verb 买 (mǎi) means "to buy" and is used to describe the action of purchasing something. It can be followed by the aspect particle 了 to indicate a completed purchase, and by an object indicating what was bought.
我昨天买了一件新衣服。
Wǒ zuótiān mǎi le yī jiàn xīn yīfu.
I bought a new piece of clothing yesterday.
她想买一本中文书。
Tā xiǎng mǎi yī běn Zhōngwén shū.
She wants to buy a Chinese book.
你在哪儿买的这双鞋?
Nǐ zài nǎr mǎi de zhè shuāng xié?
Where did you buy these shoes?