Why are there multiple ways to express "Wait a second" such as 等、等下、等一下？ I'm confused about some words in Chinese, it seems like most of the time there are multiple ways to say the same word by adding some &quot;basic particles&quot;  around it.
Like: 等, 等下, 等一下
To an online translator, it seems to mean the same. Is there any difference? Why is it like this?
As a new learner this makes listening and reading very complicated, because I never know where to cut the words in my head.
Why not?

English has the similar phenomenon. For example, the following phrases have the same meaning:
wait a bit
wait a mo
wait a moment
wait a second
wait a minute
wait a jiffy
wait a jiff

The following phrases have the same meaning:
等一下
稍等一下
稍等一等
稍等一會兒

等下 is not so common.

Usually, 等 means "to wait", not "to wait a second".
For example, 等人 means to wait for somebody.
It is different from "to wait a second".

"Wait" can mean "wait a second" in English.
等 is not the same as 等一下 in Chinese.