I have come across the following sentence in New Round-Up 3 Pearson Education Limited 2010:
I swam at the beach last weekend.
I would have understood if it were 'at the seaside', but 'at the beach' strikes me as unusual.
I have come across the following sentence in New Round-Up 3 Pearson Education Limited 2010:
I swam at the beach last weekend.
I would have understood if it were 'at the seaside', but 'at the beach' strikes me as unusual.
At least to this American, "the seaside" seems too general for the specific action of "I swam". I generally think of "seaside" as referring to a coastal area in general, though perhaps this because (at least Merriam-Websters EL definition of seaside seems to think this) in AmE seaside is most often used as an adjective (e.g. the seaside town, a seaside hotel) rather than referring to the actual coast/strip of sand where one might swim. Additionally, the word seaside to me could be connoting any portion of the coast, whereas one primarily swims at specific sandy places: the beach.
To an American ear, "at the seaside" sounds odd. "At the beach" is the most natural way of saying it. "The beach" refers to the general location of by the sea.
at the seaside,at the beach
To try to haul my random thoughts into a semi-coherent ramble - though not necessarily an answer, per se...
To a Br E ear, "the seaside" is the generic term for any coastal town, though particularly reminiscent of the heyday in the 50s & 60s of such as Blackpool, Scarborough, Margate, et al. - featuring pay-through-the-nose attractions such as the fun fair, candy floss, donkey rides, fish & chips, kiss-me-quick hats, poor beer & guest-houses with brushed nylon sheets.
We would stroll along the Prom, listen to brass bands, risk the pier in high winds & rain, perhaps venture out onto the sand far enough to paddle in the freezing cold North Sea.
An idyllic, though strangely overall dissatisfying experience; hence perhaps its decline as people in recent years have had more disposable income - so they can repeat exactly the same miserable experience in sunnier climes… such as Benidorm.
I am fine with "I swam at the seaside", as an American.
For example, "I swam at the hotel" is perfectly acceptable if I swam at the hotel's pool.
Beach is more common, but I'd prefer the additionally evocations of seaside.
"Seaside" only sounds a bit rarer to me in that it is a slightly less often used near-synonym for beach. Of course, seaside should only be used for bodies of water that can be considered seas. Lake Tahoe has a beach, but not a seaside, for instance.