我刚把明信片寄出了。

Wǒ gāng bǎ míngxìnpiàn jìchū le.

I just sent a postcard.

我寄了一封信给你。

Wǒ jì le yì fēng xìn gěi nǐ.

I sent a letter to you.

我收到从北京寄过来的包裹了。

Wǒ shōudào cóng Běijīng jìguòlái de bāoguǒ le.

I received a package sent from Beijing.