Comparing two things/people
A + 比 + B + 形容词 (一点儿/一些)This structure is used to compare two things or two people. Put noun A first, then 比, then noun B, and finally the adjective. You can add 一点儿 or 一些 to soften the degree of comparison.
这个房间比那个房间干净一些。
This room is a bit cleaner than that one.
火车比飞机便宜一点儿。
The train is a little cheaper than the plane.