"What's Teacher Li's telephone number?"
why do we need to say '电话号码' for 'telephone number'. It means same if we just say '电话'
No, that first sentence you wrote translates to "What is Teacher Li's phone?" - There's nothing about her phone number in it. The second sentence is fine except that you have a type for the teacher's name.
There's nothing wrong with saying that, actually. 你的电话是多少？is like the English "what's your number?"
No, it's not. 多少 literally means "more less" - it is used to ask "how much." Since a phone number isn't a quantity, it isn't used in this context.
If you move to china or Taiwan you will realize that people say 你的电话是多少 much more often.
I have lived in China for some time now and no one has every said this to me or within my hearing distance.
Consult your nearest Chinese friends because you are mistaken. It sounds weird in English but that is truly how many people say it.
It is possible to leave out both and just say 李老师的电话是多少 though :) But you have to either use both 号 and 码 or neither here; *电话号 does not exist.
号 is number by itself. It's in my address several times. Your cell phone number is your 手机号.
I'm just a beginner, but I think it is used here as part of the word 'number', rather than in it's own, so we don't need it again at the end, for the reason you gave, but we do need the one that is there.
Yes, and I think that this one is third tone, whereas the particle indicating a question is neutral tone.
actually why duo sha and not she ma like in previous examples with names?
I think that this actually means something like "how much" but we translate it as "what" in this context i.e. with questions about numbers, whereas 什吗 just means "what" in a more general interrogative way not involving questions about numbers.
I forgot to put ''de'' as a fourth sign and it accepted my answer. Is it okay to miss that symbol?
Is it just me or if you pick the full 多少 the speaker pronounces it duo1 sheng3? However, when you pick it character by character, it says duo1 then shao3. Is that a mistake on their part or am I hearing it wrong?
"De" implies ownership. Most sentences will show it in the form of [Noun1] (De) [Noun2]. The first noun "possesses" the second.
I would like to see duolingo give a different name or occupation when giving this lesson. That way we can get used to hearing it differently. Not just saying or writing it ourselves