A + 比 + B
比 can serve directly as a main verb meaning "to compare." In this usage, it takes two objects that are being compared. For example, 你不能比 means "You can't compare" and 我们来比一比 means "Let's have a comparison."
我们来比一比谁跑得快。
wǒmen lái bǐ yī bǐ shuí pǎo de kuài.
Let's compete to see who runs faster.
别总拿自己跟别人比。
bié zǒng ná zìjǐ gēn biéren bǐ.
Don't always compare yourself to others.
这两个没法比,完全不一样。
zhè liǎng gè méi fǎ bǐ, wánquán bù yīyàng.
These two can't be compared; they're completely different.