I saw this somewhere. In social media, I believe. I don't remember the whole sentence:
... in spite of the fact you can't deny the liminal state between exasperated and agitated. (I hope I write it correctly)
Shouldn't 'being' be there before exasperated and agitated? I mean, every time I see an adjective, I believe it has a contruction be+adjective.
In this context, exasperated and agitated are not being used as adjectives. They're being used as nouns. Specifically, they are naming conditions or states of being. It would be less idiomatic, but you could rephrase like this: "...between the condition of being exasperated and the condition of being agitated."
This kind of phrase, which uses adjectives like nouns, is fairly common. Here are some examples:
Sometimes nominalization (making a non-noun into a noun) is done by changing the word. In fact, there are related, nominalized forms of exasperated and agitated: exasperation and agitation. This sentence, could have used those forms - i.e. "...the liminal state between exasperation and agitation" - and there are probably style guides that would recommend the use of those nouns, but it's not mandatory.
Here's a useful discussion of the subject on the English Language and Usage site: Is there a term for the use of adjectives as nouns?
There's no rule that requires "be" before adjectives.
If you're comparing the meaning of similar adjectives, then it's the words themselves we are comparing, so it's more natural to omit "be":
... the difference between burgundy and maroon.
... the difference between complicated and complex.
On the other hand, if you're comparing the state of being different adjectives, particularly the consequences of those states, then "being" is required:
... the difference between being married and being single.
... the difference between being lazy and being hardworking.
In the context of your example, the meanings of "exasperated" and "agitated" are quite close, so they're more likely referring to the meaning of the words rather than the state of being.
I agree with you that it sounds awkward not to have 'being' before 'exasperated' and 'agitated'. Without it the meaning is still understood, but only because the reader infers from the context that it's referring to states of being. Writing it this way puts a burden on the reader to infer the meaning.
Without the context of 'the liminal state' you don't know what the basis of comparison between 'exasperated' and 'agitated' is. You could be comparing the difference between their first letters.
I would write it in the following way to make it very clear and relieve the reader of the responsibility of inferring the meaning from the context:
... in spite of the fact you can't deny the liminal state between being exasperated and being agitated.
