1. 一定要小心!

[ yī dìng yào xiǎo xīn ! ]

To be careful!

2. 我会小心一些的。

[ wǒ huì xiǎo xīn yī xiē de 。 ]

I will be more careful.

3. 他开车比你小心。

[ tā kāi chē bǐ nǐ xiǎo xīn 。 ]

He drives more carefully than you.