走快点，不然我们就赶不上火车了。

Zǒu kuài diǎn, bùrán wǒmen jiù gǎn bùshàng huǒchē le.

Walk a little faster, otherwise we won't be able to catch the train.

幸好你提醒了我，不然我又会忘记带我的钥匙。

Xìnghǎo nǐ tíxǐng le wǒ, bùrán wǒ yòu huì wàngjì dài wǒ de yàoshi.

Fortunately you reminded me, otherwise I would have forgotten to bring my key again.

快点做完，不然会没时间了。

Kuài diǎn zuò wán, bùrán huì méi shíjiānle.

Finish it quickly, otherwise we won't have time.