οὐδὲν [69 verses](adj sg neut nom /acc) "Nothing" is oudeis which means "no one," "not one," "nothing," "naught," "good for naught," and "no matter." -- The Greek adjective translated as "no man" also means "no one," "nothing," and other negative pronouns. It is used by Jesus more like a negative pronoun than an adjective.  However, to avoid the English double-negative, we translate it as its opposite "anyone" when used with another Greek negative.

Οὐδέποτε [5 verses](adv) "Never" is oudepote, which means "and not ever", "but not when", "nor ever", "not even ever," and "never." It is a compound of oude, and pote. Oude, as a conjunction, means "but not", "neither", and "nor." As an adverb, it means "not at all" and "not even."  Pote means "when", "at what time", "at some time or other", "at some unknown time, and "at some time in the future.  - "Never" is from a Greek word that combine an extreme negative particle with the word that means "when." The Greek negative is an adverb that means "not at all" or "no even".  The second part means "when", "at what time", "at some time or other", "at some unknown time, and "at some time in the future."

οὐκέτι [17 verses](adv) "Henceforth" is ouketi, which means "no more," "no longer," "no further" and generally, "not now."  -- "Henceforth" is an adverb that means "no more," "no longer," "no further" and generally, "not now."

οὖν [82 verses](adv) "Therefore" is oun, which means "certainly," "in fact," "really," "in fact," "so" and "then" (continuing a narrative), and "then" and "therefore." -- The Greek word translated as "therefore" either emphasizes the truth of something ("certainly," "really") or it simply continues an existing narrative, "then," "therefore." Jesus uses it to respond positively to questions, but in parables, it can continue the story.

οὔπω [9 verses](adv) "Not..yet" is from oupo, which means "not yet" and a strong form of "not" and "not at all." -- "Not yet" is an adverb that means "not yet" and a strong form of "not" and "not at all."