"elder brother" and "elder sister".

[Mars80]

Do these seem old fashioned to you? Personally I'd always say "older brother" and "older sister". "elder" sounds a bit old fashioned.

[rmanoj]

It always sounds a bit odd to me when my friend talks about his "older brother". I would probably use "elder" (if I had any siblings, that is...).

[Linguaphile]

Do these seem old fashioned to you? Personally I'd always say "older brother" and "older sister". "elder" sounds a bit old fashioned.

Like you, I say "older," but I've heard other people say "elder" as well. To me it sounds more formal, although not necessarily old-fashioned. It might also be a regional preference.

[vijayjohn]

Do these seem old fashioned to you?

Nope. (I think we Indians tend to use them relatively often in English).

[Koko]

I prefer "older" over "elder," but with the superlative i find that i use "oldest" and "eldest" nearly as often as each other. My eldest sister is coming over for dinner. for example. I think in my head, "elder" is somewhat older than "older." Both my sisters are older than me, so i tend to use "older" for the youngest of the two and "eldest" for, well, the oldest. But if i make no mention of the other when talking about them I usually just say "older." I dunno why i make this arbitrary distinction of the roots, nor where it comes from.