Here's why:
* Adjective: "Cheap" describes a quality or characteristic of something, like its price, quality, or value.
* Example: "That's a cheap shirt." (Describing the shirt's price)
You can use "cheap" as a noun in a limited sense, usually in the context of something that is inexpensive:
* Example: "They offer a cheap at the local market." (Refers to a bargain or something sold at a low price)
However, even in these cases, "cheap" is often understood as a shortened form of "something cheap".
It's important to note that "cheap" can have negative connotations, implying low quality or lack of value.