The comparative particle η (e) basically means "or", but with some additional tricks up its sleeve. It may show up twice in one sentence, and then assumes the disjunctive comparative function of "either... or" (Matthew 6:24). It comes equipped with a slight tone of inquisition and suggestion: "or [wouldn't it be that]...?" (Matthew 9:5), or even confirmation of denial: "or [as you know there isn't]...? (Matthew 7:9)."

Our particle may serve to introduce a whole comparative clause, where in English would be used the word "than" (Matthew 10:25) or alternative (rather "than", Matthew 18:3). Together with the adverb of time πριν (prin), meaning "before" it means "sooner than" (Matthew 1:18). Combined with the conjunction αλλα (alla), meaning "but", our particle forms something like "unless" or "except". Together with the copulative και (kai), meaning "and", it forms "and also" or "and even".

This particle occurs 355 times in the New Testament, see full concordance, but note that it is identical to the feminine nominative single definite article ("the"), and the nominative and dative single forms of the relative pronoun ("that").

The adverb of affirmation (or expletive, rather) η, (e), means yea or aha and occurs in the New Testament in Hebrews 6:14 only but all over the classics, usually in combination with other particles of confirmation. It differs (if it does) from the previous only through a slightly differing diacritic mark on top of it. The markings in this case emerged in the 2nd century BC and drifted out of use in the 2nd century AD, probably also because most speakers of Koine were non-native speakers (Koine was then what English is today, and back then there was no spelling-checker, so most people wrote the way the Greek sounded to them). In written texts these symbols were barely distinguishable, and in any verbal presentation probably too — we have no sound recordings from those days, but both particles are transliterated the same and probably sounded virtually identical.