When I was very young, we lived in a condo. It was basically a house that had been glued to another house. My grandma also has a condo. It is a house glued to two other houses, one on each side.
This is what a condo is. A condo is not a little box carved out of an even bigger box with other little boxes in front, behind, above, below and alongside. That is an apartment. A-part-ment. They are “a part” of the “ment.”
The only reason anyone says “condo” when they should say “apartment” is that they are trying to communicate the fact that they own their apartment. They want to bask in the prestige of owning real estate Well, whoopdeedoo, you send an outlandish check to a bank instead of a landlord each month, in addition to putting a bunch of money down on a shitty investment that won’t give you anything like the return you expect. Well done, you.
When you buy an orange at the grocer, does it magically transform into something other than an orange? No, it’s still a fucking orange. We even have this handy grammatical way to indicate that change of ownership: the possessive. Now it’s “your orange,” but it’s still a fucking orange. It’s not a “condo.” The English language, including slang, has about 50 synonyms for “car,” but none of them differentiate between the car you lease and the car you own. It’s “your car,” “your orange,” and “your apartment.”
By the way, you can totally rent a condo, which my parents did with ours after we moved to a house. Were we renting our condo whilst our tenants were renting an apartment? No. No, no, no. Besides, *someone* owns your apartment, even if it isn’t you. If the landlord moved into the apartment himself, would it suddenly become a condo? No! It would be just what it always was: an apartment.
Granted there are gray areas. It’s not totally insane to consider my current home a condo, but I still refer to it as “my apartment” because I don’t want to be a pretentious douche.
Here’s a pretty reliable test to determine whether your “residence that shares one or more sides with another residence” is an apartment or a condo:
Question: Do you have your own front door? That is, do you have your own, private, individual door that leads from the street to your residence?
If yes, congratulations! You are the proud resident of a condo.
If no, you live in a fucking apartment. Deal with it.