Here's why:
* Nouns don't belong to groups in a strict sense. There are categories of nouns (like common nouns, proper nouns, concrete nouns, abstract nouns), but these categories are based on their function or meaning, not on belonging to a specific group.
* "Desk" can be categorized in several ways: It's a common noun (not a specific person, place, or thing), a concrete noun (something you can physically touch), and it falls under the broader category of furniture.
So, while "desk" doesn't belong to a specific noun group in a formal sense, it can be grouped with other nouns based on shared characteristics or common usage.