2 sentences

1. 我是上个月来的北京。

   wǒ shì shàng​gè​yuè lái de Běi​jīng.

   I came to Beijing last month.

   Source: Tatoeba

2. 我上个月去了北京。

   wǒ shàng​gè​yuè qù le Běi​jīng.

   I went to Beijing last month.

   Source: Dong Chinese Dictionary