up和down是同类词吗

是同类词，

在谈论方向时，单词 “up” 和 “down” 一个指 “上”，一个指 “下”。但 “up for something” 和 “down for something” 却可以表达同样的含义，即 “乐意、愿意做某事

1. 用作副词，down 的基本义为“向下”或“在下面”；up 的基本义为“向上”或“在上面”。如：

He looked the girl up and down. 他上下打量着这个姑娘。

He sat down but she stood up. 他坐下，但她却站了起来。

一、本义：向上升

up 的本义是 向上升，to a higher position

(1) 具象意义：向更高的位置

up and down 上上下下 | The pop singer jumped on the stage up and down. 那位流行歌手上下跳在舞台

We walked slowly up the hill. 我们慢慢地爬上山

Tim had climbed up a tree to get a better view. 蒂姆爬到了树上，以便看得更清楚

Put up your hand if you know the answer. 如果知道答案就举手

look up the river 望向河的上游 | come up the road 来到这条路上

pick up 捡起，习得某项技能 | She picked her jacket up off the floor. 她从地板上捡起外套

go up 上升 | Production is going up in leaps and bounds. 产量飞速增长

(2) 抽象意义：提高

move up the social ladder 提高社会地位

talk somebody up 把某人捧上天 | But I am ready to talk you up. 不过我已经准备好要捧你了