What do these expressions have in common? They all seem to mean something that is redundant or self-evident, yet they don’t; instead they refer to very specific situations, people, or objects. All actors play characters, but a “character actor” specializes in a specific kind of role. It’d be impossible for anyone to use a car without seats, but a “car seat” is something you have to strap in for a baby or toddler to sit in. And unless you’re homeless, you could be said to be living at home, but it actually refers to young adults still living with mom and dad.
Are there any other examples like this in English?
No. A frat house or digs is a home, but someone living there would not be “living at home”. Ditto an exchange student living with a sponsor family for a year would not be “living at home” either.“home” is shorthand for “your own family home”
No. It’s the parts played, not the style of acting. The opposite of “character actor” is more “lead actor” (but not quite). The opposite of “method actor” is more “classical actor”.
The OP admits they aren’t redundant, but suggests that they seem to be so at first glance.
I agree that “car seat” doesn’t seem redundant but the others do. The term “home” usually means “where you live” so it does seem redundant, and the definition of “acting” is “playing a character” so that also seems redundant. But as both you and the OP mention, they are actually specific descriptors.
One I’d suggest is “tobacco cigarette”… You assume a cigarette has tobacco in it but that’s not always true.
I don’t see how that phrase seems redundant or self-evident. I just Googled “shop for seats” and nothing on the first page lead to baby seats for cars. “Shop for car seats” did.
Not even character actor? That seems redundant for obvious reasons.
If you look up redundancies or pleonasms, you will probably be able to find a few that claim to be but aren’t, necessarily.
I just found empty hole and anonymous stranger listed as pleonasms. If there were a bunch of holes in the ground and I threw a ball in one, that would be the hole that is no longer empty. Most would still regard it as a hole.
If I just found out the name of someone I was introduced a moment ago, I would still consider that person a “stranger”, although I now know his/her name.
There is one connotation of home, such that, in certain contexts, the phrase living at home is clearly understood to mean “living with one’s family.”
Otherwise, people wouldn’t be saying it, and it wouldn’t be in this OP.
As to the OP’s question: Precisely because changes in the world engender new concepts, we “re-purpose” existing words with new connotations, (instead of creating completely new words out of thin air.) That’s why we have the phrase living at home. Its meaning derives from the new, primarily American phenomenon of children being expected to leave their parents’ residence at 18. When a person doesn’t do that–or returns–it’s not the norm, and we need a way to convey it. Because it otherwise would be “redundant,” this new connotation becomes clear.
If the meanings of phrases were simply the denotational sum of their constituent parts, language wouldn’t even work. We wouldn’t be able to understand that a greenhouse isn’t a green-colored house, for instance.
Why would this be unique to English? I’m sure other language do this, too, though I can’t come up with an example off the top of my head.
That isn’t my understanding. I always thought a character actor is someone who can play a wide variety of different characters. Someone who always plays similar roles is typecast.