I (nor I think anyone else) suggested Uruk-hai/orc/goblin were different species. Also while the term "Uruk-hai" in the black-speech does literally mean orc-folk, it was reserved solely for the soldier orcs of Mordor, maybe Isengard I do not recall, who were stronger, faster and resilient to the sunlight and never for any other orc. I do not know anything about Uruk-hai or other orcs having any trouble with the black-speech, but do know that Sauron created it to be the sole language of his servants, and know that the Olog-hai only ever spoke it. Orcs in general I recall had their own heavily dialectalized language, but would imagine Sauron capable of getting his servants to speak how and what he wanted.
Sorry, I'm just tired of a lot of people (not you) who can't seem to grasp that fact...
Except for in the index, the term "Uruk-hai" was used but seldomly in the book, always to refer to "[Saruman's] fighting Uruk-Hai"
And, I can't remember anyone else besides Saruman and his Uruk-Hai themselves doing so: I think the good [and other bad] guys just called them orcs, could be mistaken though.
The orcs had many regional dialects (with a few shared B.S. words mixed in), each group having their own version; the difference was so bad that sometimes they would have to (poorly) use the common tongue of men to communicate between tribes (that's why Merry and Pippin could understand their captors).