"为何“ versus ”为什么“ and ”何时“ versus ”什么时候“
问一下，what are the differences between those? 为何 and 何时 are more formal?
tingyunFebruary 16, 2011, 02:43 AM
Yes, and much more formal. 何 is the most often used question word from literary chinese, meaning the same as 什么.
Other common examples from literary chinese (or very formal modern written chinese) are 何以 (literally, using what, often used more abstractly to mean why or how), 何人 (什么人), 何不 'why not' (ie rhetorical question to suggest doing something) (sometimes abrevated as 盍he2, which is a contraction of 何不),何等，何其，何许 (often used with a literal meaning of 'what kind' but the sense of exclamation and high degree, ie in 何其_ _ (insert a two charecter adjetitive) it is literarlly asking 'how much _____' but its meaning is 'very _____'), 何故 (what reason), 何尝 (尝chang2 is sort of like 曾ceng2 in indicating something happened, so this is used for rhetorical questions like 我何尝不想? which has a meaning of 'I do want it/think about it'). And generally 何finds it way into all sorts of very formal, not really used anymore ways of saying things - ie 他们与你何干（gan1） vs the modern 他们跟你有什么关系 (though the literary version is definitely not asking about what kind, but rather asserting lack of a relationship, while the modern can have both senses, though I think that probably has more to do with the switch from 干gan1 to 关系) or 您有何贵干（gan4）？vs the modern 您有什么目的/想做什么.
In modern use, the most common thing to encounter is probablly 如何 used in place of 怎么, though this is still rather formal, as well as the two examples you menotioned. There are also a few things like 几何, literarly 'how many', but often used now as the term for gerometry, and there are some expressions like 何乐而不为 'why not' in the sense of saying a thing should be done (Actually the final 为 is wei2, and doesn't mean 'to act', but rather is a particle indicating a rhetorical question that often pairs with 何 in literary chinese, with the two of them marking the begining and end of the rhetorical question - though I think this may idea may have faded in many speakers minds as the structure solidified into an expression, else its hard to understand why people often add a 呢, which only makes sense if you take 为 as indicating action, and not itself marking the question), or 何年何月 (what year, what month, implication is I have no idea when it will happen usually because its a distant event or might not happen) and such expressions.
Sometimes it used to be replaced by 曷he2 with the same meaning, but for formal modern chinese 何 is the default choice.
Well, there are odd places where formal language like that fits well - for example, internet chatting away messages and status updates (which of course also allows for very colloquial). So I think its fine to test the waters a bit with using formal language - and through misjudgments start developing a sense of when to use what.
Then there's always purposefully using such things as a joke, for example the next time someone thanks and compliments you on something you did, you can try replying with: 区区小伎，何足道哉(zai1) (such a small display of skill, how could it be sufficient to speak of 啊) ;)
And if you try writing, the standard of eloquence (at least as articulated by many scholars) in formal written Chinese is a bit counter intuitive - it's a mix of both formal and colloquial language, intermixing not only between sentences (ie 2 formal sentences, 3 informal, 1 formal, 1 informal, etc), but rather within sentences, and even within clauses, in a constant transition from formal to informal phrasing and back again. Very different than English, which is probably closer to admiring purity in constantly using formal language.