329. Under the term particles it is convenient to group together a number of words that are mainly used to show the relations between other words, and between clauses. In respect of this office they are akin to the various syllables or letters used as endings, and with them go to constitute what are called the formal elements of the language, in contradistinction to the roots or stems which compose its "matter."
The particles which connect successive clauses in any way form the conjunctions. As such they may be distinguished, according to the nature of the connection which they indicate, as copulative (καί, τε, ἠδέ, etc.), adversative (δέ, ἀλλά, αὐτάρ), disjunctive (ἤ . . . ἤ), conditional (εἰ, ἄν, κεν), Illative (ἄρα, δή, οὖν), causal (γάρ), etc.