Quisquam and quispiam, quisque and unusquisque... (Seemingly synonyms)

I am having a hard time differentiating some interrogatives, because their meanings are seemingly the same. For example: for quisquam Lewis & Short gives any, any one, any body, any thing, something; for quispiam, it gives any one, any body, any thing, any; some one, something, some. For quisque it gives whoever or whatever it be, each, every, every body, every one, every thing; for quicumque, Whoever, whatever, whosoever, whatsoever, every one who, every thing that, all that; for unusquisque it doesn’t even has a separate entry: it is in unus, II, B, 5, and it doesn’t point any difference from quisque.
Are these just synonyms? Or there is some subtle difference between quisquam and quispiam, between quisque, unusquisque and quicumque?

These are not interrogatives, John, though of course they can be used in questions.

quisquam means anyone at all, usually in negative context, while quispiam, less common, means some(one). quisque means each one, unusquisque each single one. Etc.etc. But one-on-one English equivalents are less useful than actual examples, where you can observe the usage.

Lewis & Short is a decent dictionary despite its age, but the Oxford Latin Dictionary is much better, though I suspect it’s more than you need at this point. I would advise you to read some real Latin as soon as possible, and to use a dictionary only in that context.

These are not interrogatives

I know; I somehow confused indefinites and interrogatives. I even did that in my own notes!

Much thanks for the help, both in this and in my later post (about relatives and interrogatives)!