British English in America

Flat has been in common use here since before I was born, and I'm retired. Chicago, where I live, has dwellings that are commonly referred to as two-flats, three-flats, etc., up to six-flats. (Something larger would probably be called an apartment building.)

NA, I think that may be regional. From Wikipedia "In cities such as Buffalo, Detroit and Chicago the term Two-flat is used and defines it as a 'residential building that contains 2 dwelling units located on a single lot'." A quick Google search turned up mostly chicago hits.

Certain, around here, I've never run into a flat. A building with two units is a "duplex." There are also triplexes and fourplexes or quadplexes. (It's my understanding that in New York, a duplex is an apartment that has two floors.) A duplex is usually one story with the units side-by-side. A fourplex usually has two on the first floor and two on the second floor.

Those are usually purpose-built, rather than older buildings chopped up. I once lived in a big 19th C. house that had been converted to three units. That house wasn't a triplex, nor was it an apartment building; it was just an old house that had been converted to apartments.

"Frock" seems to be a returnee. I've run into it in fiction, etiquette books, and old magazines from about the 1920s up to the 1950s or so.

Some older folks in the U.S. still refer to jeans and slacks as "trousers" and you occassionally see advertisements for "trousers" whereas most younger Americans refer to such articles of clothing as "pants."

'Trousers' for trousers in the south of The UK.
'Pants' for trousers more so in the north.

A duplex is usually one story with the units side-by-side.

There aren't many duplexes in the Chicago area, but they tend to be two-story homes, side-by-side but within one structure. The drawback was when one owner didn't keep up his side of the building, so that window frames, eaves, etc. on one side might be freshly painted while paint on the other side was peeling.

Are there people in America who still think that the world is apartment? :-)

I heard a property description in Manitoba.... "Side by side".
Does that refer to what in The UK would be called a terraced property?

The drawback was when one owner didn't keep up his side of the building

A duplex here is always a rental. Sometimes the owner lives in one unit & rents out the other. So the owner is responsible for upkeep, not the tenants.

If it were two owned units it would probably be called a condo.

The 10-year olds who come to my volunteer program rarely know the word "trousers." They also don't know "Levi's" as a generic for jeans.

In the Chicago area, condominium denotes a particular kind of ownership under law that didn't appear until the 1960s. Duplexes were around soon after World War II. The ownership was some other form that may be extinct now.

In Toronto there were flats, which were dwellings rented out in somebody's house -- for example, the owner lived on the ground floor and rented the second floor, but it wasn't really closed off and they had a common entrance. This was often done to help pay for the house rather "unofficially", but in the want-ads, there were sections advertising flats and others advertising apartments.

Last time I was in Canada, I heard the term "granny flat" for a small apartment in the basement of a house.

A duplex in Toronto was a 2 floor building (that looked more like a house, so with one entrance and staircase) but with 2 separate apartments in it; a triplex would be 3 separate apartments, one usually a semi-basement, the two others above. I don't remember the usage of four-plex -- I guess it would have become an apartment building at some point.

"Frock" to me is a very old British usage that I knew as a kid in England. Lately, I have seen it used in the fashion pages of the International Herald Tribune but it strikes me as a bit pretentious.

Seeing #20, I add that apartment buildings used to have apartments that were only rented out, but since I left, they sell the apartments and they are called condos. I understand they have enormous maintenance fees. On my latest visits to Toronto, that's all I saw being built -- condos. But rental apartments still exist.