Translation:They are my older brother and older sister.
In Taiwan the character "和" is pronounced as "hàn" when meaning "and." Since "和" is frequently used, this difference in pronunciation can be a simple tip to tell the people from mainland China or Taiwan. By the way, unlike Japanese, Chinese characters with multiple pronunciations are in limited numbers, but "和" has 6 pronunciations -- Maybe the character with the most pronunciations in Chinese.
I answered "they are my older brothers and sisters" and it demanded "they are my older brothers and big sisters" (sigh)
I believe it is as well correct without repeating older. "They are my older brother and sister" have the exact same meaning like "they are my older brother and big sister". Moreover big is a measuring word for size not for age.
In English (or US English at least) "big brother/sister" is universally understood to mean "older brother/sister," regardless of the siblings' actual relative size. You wouldn't use it in academic writing but in everyday speech and most written English it's totally acceptable.
It's said English in general not just US English. However, it is typically said by children not adults, or is used as a cutesy way of speaking.
Apparently not here. As far as I know the Chinese language has a separate word for 'siblings'.
Exactly. Why grade the English grammar? There is no need especially when it is wrong or stilted.
How can one distinguish the number of siblings in this sentence? I've seen "older brothers and sisters" and "older brother and sister" accepted.
In English bigger can mean older, but typically only for children, because their older siblings are normally bigger, because, obviously, they're older.
Do people say older brother and big sister? In my experience it is either big brother and sister or older brother and sister....they have the same meaning, why do they insist it is wrong?! This has happened to me several times, like with 没关系 where no problem, or don’t worry about it etc. should still work.
Not in Chinese. It is culturally necessary to specify because it often denotes how they are to be treated. In Mandarin you need to specify that both mean older
I put in 'They are my sister and brother' without any 'older' and it got accepted. I don't understand the difference between the characters with and without 'older'.
Sometimes Duo requires the older/younger and sometimes it doesn't when translating to English. As it is required in Mandarin I always translate them into English anyway just to remind myself of the importance of the distinction in Mandarin, even though it is often not necessary in English. It also helps me remember which is which in the Mandarin characters.