Comparing quicumque, quilibet, quisquis, quivis

Question

The pronouns quicumque, quilibet, quisquis and quivis have a somewhat similar meaning, roughly "anyone". What exactly are their differences? The dictionary entries I have seen do not provide a clear comparison between these pronouns. Is there perhaps an example sentence where one can grammatically use any of these words but the meaning or tone is different?

To some extent this was explained in this question about quisquis and quicumque, but I would like to know how the other two pronouns fit the picture.

Answer 1

quisquis and quicumque are relative pronouns, so they introduce a restricting clause:

Quisquis es, noster eris. Whoever you are, you will be one of us.

...scilicet omnibus quicumque terrae munere vescimur enaviganda. ... (which) all of us who feed on the bounty of the earth will surely have to sail through.

By contrast, quivis and quilibet are indefinite pronouns, so they don't have a clause of their own:

Non cuivis homini contingit adire Corinthum. It doesn't fall to everyone's lot to go to Corinth.

Quemlibet, modo aliquem. Anyone, as long as it's someone.

(Note that quivis and quilibet in the negative mean "not every", whereas quisquam in the negative means "not any".)

Answer 2

Additional:
Quisquis, quidquid, are used colloquially for quisque, each.

ut quidquid. Properly quisquis is an indefinite relative: in this usage it has the same force as quisque (Roby, 2283, 2285). It may have been an archaism which became colloquial.(undoubted instances occur in Plautus, Terence, Cato who capture everyday speech).

It is also found in poetic philosophy --

Lucretius (with whom it is especially common: e.g. ruit qua quidquid fluctibus obstat, i. 289), and golden age oratory-- Cicero (Tusc. v. 98), and in the Agrarian Law (utei quicquid quoieique ante h. l. r. licuit, ita &c. Mommsen C.I.L. 1 n. 200 v. 27). Cp. vii. 2, 35.

So too in this famous ancient grammar book

Corn. ad. Herenn. ii. §47, where the MSS. almost without exception give quidquid (quicquid) for quicque.

Source: http://www.gutenberg.org/ Quintilian Bk X Notes on the opening paragraphs.