Translation:Teacher Li has two younger brothers.
I was wondering if using the "er" word for two is OK here. But presumably not? If teacher Li had 3, 4 or 5 brothers, would we use the ordinary numbers, 三、四、五? san, shi, wu? But with 2 it seems we use this "both" type word? I guess English has something similar, with certain special words for two, like "couple" or "pair" or "brace". Just trying to understand - would 二 "er" be wrong here? Or just sound unnatural? Thank you
Yes and no. In putonghua / Mandarin, 一 must change tones related to the following word, 二 and 两 have different usages, but other numbers are regular. In some dialects the numbers may vary differently, e.g. in Shanghai 222 reads 两百廿二 (cf. Mandarin 二百二十二 or 两百二十二), where 廿[niàn] is a surviving ancient form of 20. BenjaminTh276643's mention of reading 1 as 幺 is also general, but in some specified contexts: e.g. to read numbers individually, and/or in technical, card games, or some other specified fields, where confusions between 一 and 七 are not desired).
In cases where counters are present, we usually use 两, as in 两个弟弟 with the counter 个. There are some exceptions, e.g. if the counter is 两 [a traditional unit ~ 50 g], for some obvious reasons, we have to say 二两 rather than 两两, as in 喝二两 [drink 2 liang (of alcohol); a dose of 100 g or 100 mL (approx.)]. 二 could be also used, but in a different word order and in more formal (written, and even classic-Chinese-like) fashion: 兄弟二人 [two brothers]. In the former ￥2 bill, the text reads 贰圆 [two yuan; 贰 is used instead of 二 against modifications], but in daily spoken Chinese it is called 两块钱 [块 is the spoken word for yuan. ]
Collectively, brothers = 兄弟 and sisters = 姐妹 The parents in this scenario can call their boys "老大，老二，老三...“ based on when they were born （老大 is the first born, 老二 is the middle child, and 老三 is the youngest in this scenario...老一 is never used for some strange reason...) So you can say "老二有（另外）两个兄弟“ or "Brother #2 has two (other) brothers"; however, people might laugh when you say "老二” because it also has a slang meaning of a certain male sex organ...
Because you've never spent time with the Chinese diaspora in western countries.
Because the point is to translate it into English, the way an English speaker would say it. Using literal translations can get you into trouble. "Li Teacher" makes sense but a native English speaker wouldn't say that. In some situations, a literal translation would make absolutely no sense at all, so it's best just to use a more natural translation in all cases, even if a literal one makes sense.
You must use 'liang' if 'ge' (or other counting word) is the next. ' er' - is just the digit (for phone or some other number). The rule is for er/liang only.
Ну вы поняли, да? Двойка как эр только в номерах. Если речь о предметах, животных, людях и т.д. - т.е. там где обязательным к употреблению счетное слово - там надо лиан. Мы парами ботинки с носками считаем, а у них все что два - то пара. С другими цифрами - без выкидонов.
This isn't mainland China. Overseas Chinese and other cultures use Lee and it's the same character.
A previous question did not allow me to use 'Teacher' for '李老', and instead suggested 'Miss' as the correct answer (even though the term does not specify gender). I used 'Miss' to answer this question and it said my answer was incorrect and to use 'Teacher' instead. Either could be correct.