Examples
wǒ我gāi该zǒu走le了，yào bù rán要不然wǒ我huì会chí dào迟到de的。
我该走了，要不然我会迟到的。
I have to go, otherwise I'll arrive late.
今天天气很冷，您多穿衣服吧，要不然会感冒的。
It's really cold today. You should dress warmer or you might catch a cold.
我对这个政府的印象是，他们需要强一点儿的经济政策，要不然将来会遇到很大的问题。
My impression of this government is that they need a more forceful economic policy, otherwise they'll encounter large problems in the future.