前天我去了商店。
qián tiān wǒ qùle shāngdiàn 。
I went to the store the day before yesterday.
前天的天气很好。
qián tiān de tiānqì hěnhǎo 。
The weather was very nice the day before yesterday.
你前天做了什么？
nǐ qián tiān zuòle shénme ？
What did you do the day before yesterday?