誰もそのなぞを解くことができなかった。

who

too; also; in addition; as well; (not) either (in a negative sentence); both A and B; A as well as B; neither A nor B (in a negative sentence); even; as much as; as many as; as far as; as long as; no less than; no fewer than; even if; even though; although; in spite of; further; more; again; another; the other

that (something or someone distant from the speaker, close to the listener; actions of the listener, or ideas expressed or understood by the listener); the; um...; er...; uh...

something; what; why; how

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to untie; to unfasten; to unwrap; to undo; to unbind; to unpack; to unsew; to unstitch; to solve; to work out; to answer; to dispel (misunderstanding, etc.); to clear up; to remove (suspicion); to appease; to dissolve (a contract); to cancel; to remove (a prohibition); to lift (a ban); to raise (a siege); to release (from duty); to relieve; to dismiss; to comb (out); to card; to untangle (hair)

thing; matter; incident; occurrence; event; something serious; trouble; crisis; circumstances; situation; state of affairs; work; business; affair; after an inflectable word, creates a noun phrase indicating something the speaker does not feel close to; nominalizing suffix; pretending to ...; playing make-believe ...; alias; aka; nickname; alternative name; also known as

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

to be able (in a position) to do; to be up to the task; to be ready; to be completed; to be made; to be built; to be good at; to be permitted (to do); to become intimate; to take up (with somebody); to grow; to be raised; to become pregnant