我忘了带手机，结果要特意跑回家一趟。

Wǒ wàng le dài shǒujī, jiéguǒ yào tèyì pǎo huíjiā yí tàng.

I forgot to bring my mobile phone, so I had to make a special trip home.

原来餐厅九点关门，让我白走一趟。

Yuánlái cāntīng jiǔ diǎn guānmén, ràng wǒ bái zǒu yí tàng.

It turns out the restaurant closes at 9, so I came for nothing.

我走了几趟楼梯。

Wǒ zǒu le jǐ tàng lóutī.

I walked the stairs a few times.