slow用作副词时，通常只和少数动词(如go, drive, pass, run, climb等)连用，且必须置于其后。slowly用作副词时，其位置比较灵活。两者都可表示“慢”，但slow通常只与少数动词(如 go, drive, pass, climb, run, walk等)连用，且应置于其后;而slowly则用法较广，且可置于动词之前或之后，有时还可置于句首。

He walked slowly [slow] up the path.他沿着那条小路慢慢地走着。

She slowly opened the door.她慢慢地把门打开。

Slowly, things began to improve.情况渐渐有了好转。

Negotiations were going slowly, and not well.谈判进展缓慢，也不顺利。

It is a good habit to eat slowly.吃东西慢一点是好习惯。

slow(用于非正式英语中)缓慢地，慢吞吞地。

通常只与go, run, walk, drive等少数动词搭配,其比较级是slower。例如

My watch runs slow.我的表慢了.

How slow this train goes!这列火车开得多慢啊!

Tell the driver to go slower.告诉司机开慢些。

slow还可以与分词构成复合词。如:slow-cooked food用文火烹调的食物

go slow(指工人)怠工;减少活动。

You ought to go slow until you feel really well again.

你应该减少活动，直到真正康复以后再说。

slowly可用于各种情况,置于动词前或后，其比较级是more slowly。例如:

walk/speak/learn/react slowly走、说、学、反应得慢

She slowly opened the door.她慢慢地打开门。

He did everything very slowly.他无论做什么事都是慢腾腾的。

Would you please say that again more slowly?请你更慢地重复一遍，好吗?