"Soy mayor que mi hermana."
Translation:I am older than my sister.
From the best of my knowledge, "mayor" is more formal and polite to use when referring to the relative age of someone, whereas "viejo" is, in some countries, considered rude to use in reference to a person or group. In general, if it's a person's relative age, use "mayor". That said, I'm not a native speaker so there may be some more subtleties to it that I'm not aware of.
The diference is a bit like Un/a mayor person/a = an elderly person Un/a viejo/a person/a = such an old person (so it is really unpolite) but for a dog or a painting for example its normal cause you wouldnt use elderly there Dont know for sure in some spanish countries but it is that way for castellan
In addition to being the question word "what", "que" acts as a conjunction in Spanish, similar to "than" and "which". It does so in just about every romantic language. "Soy mayor que mi hermana" is "I am older than my sister." The easiest way to remember, probably, is that you wouldn't say "I am older of my sister" in English, and you wouldn't in Spanish!
the current question is in the comparative degree. Mayor is used to mean "older" when referring to people.mejor on the other hand means one thing is better than the other.
Maria es mayor que su hermana Gina Eres mejor hombre que yo. You are a better man than I.
Comparative: mayor (older; greater) Comparative: mejor (better)
that's what i think...
Older is comparative, and you can say "these boys are older than those boys." But elder is more like members of a set, and also on its own it is a noun, so we say "this boy is the elder boy", "the elder of these two boys" or "the elders of the town." Also elder is usually about people, so if you use it for something else you are personifying a bit, and implying something about dignity and respect.
Oldest and eldest overlap, you can use them interchangeably in a lot of places. Oldest can be used for anything at all, while eldest usually refers to siblings and has nuances of responsibility and maybe inheritance.