Can the word "special" have a negative connotation?
"Special education" is the usual U.S. term for the department of a public school that works with children with severe learning or mental disabilities. The term uses the word "special" in its original definition of "unique" or "different", as a euphemism to replace terms used previously such as "slow class" or "MR class".

capitalization - Capitalize fields of study? - English Language & Usage ...
Below user Robusto's foregoing answer, user Clément requests sources which I provide here: An Internet search yielded this which then recommended this by the University of Sussex:

Is "when" a preposition? - English Language & Usage Stack Exchange
I had to come up with an "edit-the-mistakes" worksheet for a Special Education student on-the-fly. One of my offerings was this sentence: When I was three years old I can tie my shoes. I had intended the correction to be this sentence: When I was three-years-old, I could tie my shoes.

capitalization - "Masters degree" — capital M or not? - English ...
The word "master's degree", used generically, means the degree attained by a master. For example, using it in this sentence is correct:

What's the correct way of saying that one is pursuing a degree?
This has now changed with more than 50% of secondary school pupils going on to tertiary education, a more representative percentage of the UK's public sector. Reading law, history or whatever is still to be heard and in use by students and alumni of Oxbridge and the older universities in the UK. Its usage, as far as I know, is confined to the ...

A word for someone who loves searching, learning new things?
"In the diffusion of innovation theory, the minority group (comprising about 14 percent) of population which, after innovators, is first to try new ideas, processes, goods and services. Early adopters generally rely on their on intuition and vision, choose carefully, and have above-average education level.

capitalization - To capitalize "department" or not - English Language ...
When using the word 'department' (or 'group', 'committee', and the like) as part of a recognized name it would be capitalized:

Word that describes both skills and experience together
In the United States, under the Federal Rule of Evidence 702 (FRE), an expert witness must be qualified on the topic of testimony. In determining the qualifications of the expert, the FRE requires the expert have specialized education, training, or practical experience in the subject matter relating to the case. Expert witness, in Wikipedia

In legal citations, why are "see", "see also", etc., in italics?
Well, going pro se to my son's special education impartial hearing, which lasted ten days, writing the closing argument, and writing a 40-page petition of appeal, have already made me well aware of my lack of legal training. Please don't rub it in!

An inoffensive word for "stupid"? - English Language & Usage Stack Exchange
Another euphemism was that class for less-smart kids were called "special education", and so the kids were called "special". You could use "silly" or "cute" in some contexts. But in general, I'd avoid looking for any word that means anything remotely like "stupid" if you're trying to keep a conversation friendly.