Was determiniert das Vorfeldkomma?

There is a peculiar comma in German texts, the prefield comma (Vorfeldkomma). It appears before the finite verb form (German is a verb-second-language). If the prefield is not a sentence and if it is not sentence-like by itself, the orthographic norm does not license a comma. However, it is found frequently in non-standardized texts. In this paper, we investigate nearly 1,000 prefield commas from a non-standardized corpus. These comma prefields are compared with prefields without commas, and the conditions are formulated under which commas become probable. The probability for a prefield comma is high if the prefield is a prepositional phrase, if it functions as an adverbial modifier, if it is long (five or more words) and if it is semantically textconnective. A prototypical example might be Neben Diskussionen über die aktuelle politische Situation, finden Erhaltungsarbeiten auf dem Gelände der KZ-Gedenkstätte statt (‚Apart from discussions about the current political situation, maintenance works are taking place on the site of the KZ memorial place‘).