How can you discern which meaning of 怎么 as an interrogative should be used in a sentence?

Question

In Mandarin, 怎么 has three major meanings as interrogatives - how, what, and why. It is quite perplexing for me to understand which interrogative someone tries to ask in.

For example, when I posted in WeChat that my weather app predicted the today's weather terribly in Shanghai, my friend added the following comment:

怎么又到上海了。

However, while I assume she tried to ask me "Why have you come to Shanghai again?", it can also be translated as "How have you come to Shanghai again?", which I will reply with "In flight".

Sometimes it is difficult for me to understand why this word has three interrogatives and which one is correct in the context. I also wonder why people don't avoid the potential conflict of meaning and instead just use a more easily recognizable word like 为什么 and 什么, if possible.

Or do Chinese people discern this difference pretty easily? Or is it completely dependent on the context? Any tips on discerning it better?

Answer 1

Ermm, you posted " that my weather app predicted the today's weather terribly in Shanghai, "

Which I presume to mean: "Today's weather in Shanghai will be terrible."

That is the context: The weather.

There is no reason for your friend to then ask how you got to Shanghai, that lacks coherence. Her or his comment:

怎么又到上海了。 means: 'How come we are getting bad weather in Shanghai again!'

怎么How又again到to上海Shanghai了。

Answer 2

• In this sentence, the key work to figure out the meaning of "怎么" is "又", which pointed out that it was not your first trip to the city. So the sentence could mean "Oh you are here in Shanghai again, why/for what?" instead of "Oh you are here in Shanghai again, how did you travel to here this time?". The latter would be weird, because If your friend wanted to know how, there's no need to point out that was not the first time you are in that city. I think the same applies to English too.
• About how to discern the difference of what "怎么" stands for, I would say, it's based on the context. Sometimes the sentence itself could contain enough information to be your context. For example, when it means why, it usually comes with the reason why the person would ask in the same sentence. In the above sentence, because you went to the city again, your friend would wonder what was that for this time. Another example "你怎么总是迟到", the word "总是" which means always, is the reason why the person wonders. When it means how, it usually would be pretty straightforward, eg. "你是怎么来的?" which means how did you come to here?
• But sometimes the context is not in the same sentence, eg. "你怎么知道的？" It could both mean "how could you possibly know" and "why you would know that" without proper context.
• As for when to use "为什么" instead of "怎么" for asking the reason, well, to me the former could be more formal then the latter.

Answer 3

怎么又到上海了.

It is not conventional writing, but means for casual conversation. So it is inappropriate translate it to English :

"hey , I see you came to Shanghai again." .

You should interpret it as "What's bring you back to Shanghai"

It is more literate to say

是什么风把你吹回来上海？