In this paper, we analyze written sentences containing the German particlesobwohl(“although”) andweil(“because”). In standard written German, these particles embed clauses in verb-last constituent order, which is characteristic of subordinated clauses. In spoken and – as we show – nonstandard written German, they embed clauses in verb-second constituent order, which is characteristic of independent sentences. Our usage-based approach to the syntax – graphemics interface includes a large-scale corpus analysis of the patterns of punctuation in the nonstandard variants that provides clues to the syntactic structure and degree of sentential independence of the nonstandard variants. Our corpus study confirms and refines hypotheses from existing theoretical approaches by clearly showing that writers markobwohlclauses with verb-second order systematically as independent sentences, whereasweilclauses with verb-second order are much less strongly marked as independent. This work suggests that similar corpus studies could provide deeper insight into the interplay between syntax and graphemics.