quisque

Quisque, quaeque, quodque as an adjective, quicque or quidque as a noun, declines like quis and qui with the enclitic -que welded on. That means the case ending sits in the middle of the word: cuiusque, cuique, quemque, quoque, and the last of those is why the adverb quoque, "also", looks confusingly like a form of this pronoun.

Quisque is unemphatic and almost never opens its clause. It hides behind three things in particular. A reflexive: suum cuique, "to each his own". An ordinal, counted inclusively: quinto quoque anno is "every fifth year" by Roman reckoning, which is every four years by ours. And a superlative, where the idiom catches everyone once: optimus quisque means "all the best men", not "the very best man". Finally, keep the family apart. Quisque is "each"; quisquam is "anyone at all" and lives in negatives; quisquis is "whoever".