我没留意前面有台阶，差一点绊倒了。

Wǒ méi liúyì qiánmiàn yǒu táijiē, chà yìdiǎn bàndǎo le.

I didn’t notice the step ahead and almost tripped.

小心台阶。

Xiǎoxīn táijiē.

Watch your step.

他这么做是为了让她有个下台阶。

Tā zhème zuò shì wèile ràng tā yǒu gè xià táijiē.

He did that to give her a way out.