Negative Adjuncts Of Modality And Temporality

Halliday & Matthiessen (2014: 187):

Adjuncts of modality and temporality containing the feature ‘negative’ have the special property that, when they occur in thematic position, the order of Subject and Finite is typically reversed; e.g.

Never before have fans been promised such a feast of speed with reigning World Champion Ove Fundin sparking the flame that could set the meeting alight.

This is a relic of an older pattern whereby the Finite operator always followed immediately after the first element in the mood structure (a pattern still found in other Germanic languages). It is not very widespread in current usage, being restricted largely to certain styles of narrative, and to public speaking.