Which grammatical rule is being used here? I thought it’d be easy to say “I didn’t do well on my exam/I did poorly on my exam” but turned out it’s not an easy one.
I have tried to translate it multiple times and here’s what I got (I’ve tried to look for each of these following sentences in Google and all of them exist, even being spoken by native) :

a. 考试考得不好
b. 考试考不好
c. 考试没考好
d. 考试差了

I won’t be asking about each of them here though. My questions are :


In sentence a (考试考得不好), what does 得 here indicate?


Is it “potential complement” or a simple “得 particle (that’s usually being explained along with the other two de &gt; 的, 地)”?
I mean, how do native Chinese speakers see “didn’t do well on an exam”?
Do they see it as one’s inability to achieve something (which means I most likely should use potential complement), or,
Do they see it simply as an adverb to show how one does something &gt; didn’t do well on an exam/did poorly on an exam (which means I can simply use 得 as a particle instead of complement)


If potential complement turns out to be the case here... Based on what’s written in &gt;


https://resources.allsetlearning.com/chinese/grammar/potential_complement :

The only difference between the affirmative and negative forms is swapping a 得 for a 不.

Then why does sentence a (考试考得不好) exist whereas we don’t need 得 to make a negative form in potential complement?
I know Chinese grammar isn’t as strict as English but just... Why? ㅠㅠ
That’s all for now.
Sorry if this question sounds stupid and that maybe it’s just me because anyone else finds it just easy to express such thing in Chinese. I don’t find it easy though.
&quot;得&quot; in &quot;考试考得不好&quot; is a &quot;degree/result complement&quot; that indicates 'the degree' of a verb, or 'the result' of a verb

考试考得不好 = [考试(to take exam) - 考得 take exam to the result of - 不好(not good)]

or

考试考得不好 = [考试(to take exam) - 考得 take exam to the level of - 不好(not good)]

More detailed example:

考试考得不好，祇得到  D 平均 - the result of the verb was bad)
考试考得很吃力 - the degree of the verb 'taking exam' is at the degree of 很吃力 (laborious level)

Side note: 得/不 as potential complement:
考得好试 = able to take exam well
考不好试 = unable to take exam well