Context, context, context

[Concerning οὖν] As with the other particles, we do not interpret utterances by deciphering a code, but by a process of inferencing which may use semantic concepts but which then draws out implications from contextual and encyclopaedic information. Putting it simply, it is not the ‘meaning’ of individual words that give understanding of utterances, but the whole background of shared knowledge between speaker and hearer as well as the surrounding narrative.—Margaret Sim, A Relevant Way to Read, 96