Interrogatives themselves are not so hard to understand or use. What you may not know is that there are even more less used interrogatives in Japan aside from the simple 誰, 何, いつ, どこ, and 何故.
何らか, also 何某か, means "any" or "some". Both of these words are quantity words. So, they describe indefinite amounts. 何らか is the most common.
A certain sum of money
To have some effect come out.
Do you have any evidence for your statement?
In some way or other
なにがし (某・何某) is a somewhat old-fashioned indefinite pronoun meaning "a certain". It equates in meaning to the Sino-Japanese prefix 某 read as ぼう. 某‐ can be used after proper nouns, place and time words. It is very similar to ある・或る. ある can be used to refer to something when one has no certainty of the actual matter/thing. When one uses 某‐, though, one knows exactly what the subject (matter) is. You just think it is best not to say it. It also sometimes gives the impression one is hiding information, especially when you overuse it. It goes well with more stiff 書き言葉. However, there are exceptions.
|ある国 → 某国||ある日 → 某日||あるところ → 某所||ある雑誌 → 某誌|
|ある会社 → 某会社||ある先生 → 某教師||ある省 → 某省||ある月 → 某月|
|あるテレビ局 → 某テレビ局||ある人 → 某氏||あるタレント → 某タレント||ある高校 → 某高校|
A certain someone from somewhere
The ら in 何ら is the same as in 彼ら. So, this is essentially the plural form of what. It is used as a more emphatic way of saying なにも. It may be used adverbially and nominally. It is not as common as なにも.
I have no fear.
I have no doubt.
There's no profit/benefit whatsoever.
いずれ, an alternative to どれ, is best translated as either "either", "both", or "sooner or later". These usages are distinguished easily from each other. If used as an adverb, it means, "sooner or later". If used with a particle such as も, it's like どれも to mean "either/both".
You'll understand sooner or later!
I will come again in the near future.
11. いずれ劣らぬ (Set phrase)
Interrogative Note: Do not get the impression that these are all of the possible interrogatives in Japanese. You will discover more, though more likely rarer, interrogatives as you continue to study Japanese. The examples below are just to show you what more is out there. You don't have to remember this stuff.
いずくんぞ, formally and formerly as いづくんぞ, means どうして. The following characters have been used to write it, but only the last is ever seen today: 悪・安・寧・焉.
How would you know death if you've yet to know life?
Confucius said, "How could you possibly serve the divine well if you can't even serve man well?"
How is that sparrows and swallows have greater will power than large birds?
You don't need a butcher's knife to kill a chicken.
Why would nobles and shogun have seeds? (Any person can achieve through effort and luck)
17. いずくんぞ知らん。(Very old-fashioned)
How would you know?
This is dependent on the much needed strenuous efforts of a pioneer who will alert the public's attention and strongly ask what the most important thing to this problem is and where the solution is.
From 國語國字問題 by 福永恭助.
1. 那辺 is a rare interrogative equivalent to どこ・どの辺．
2. The example was written before simplification took place. Notice how many characters look different.
如何 is sometimes read as いかん. This is a contraction of いかに. Both words are equivalent in meaning to どんなに. いかん is seen in formal situations, but its usage has continued to go down. いかに is used even less, but it survives in set phrases and in common usage in things like いかにも, which is used to show agreement in the same way as 全く and なるほど.
How should man live?
What should we do with this case?
Interesting Dialect Phrases
If we include dialectical interrogative phrases, the number of such phrases in Japanese goes up a lot. Some phrases are localized to very small areas, but they're still interesting to look at. Below are phrases from 福島弁. Of these なして, also happens to be used in many other places in Japan. The rest are quite localized to the 東北 Region.
Why are you crying?
The following phrases and translations are taken from the Wikipedia page on Fukushima Dialect.