For sentence grammar as well as for text grammar (specifically, narratives), various models have been established in the field. The research theme Architecture of Grammar Systems aims to explore how building blocks of such grammar systems apply in other domains and what this means for the architecture of sentence grammar and text grammar. Structured organization occurs not only at sentence or at text level, but also in speech act sequences, in child and adult atypical language, and other domains of communication (multi-modality, code-switching, iconic and animal communication, music), and complex thought formation in ways that resemble sentence or text grammar. However, these grammar-like abilities seem to not always allow all mechanisms that are available in typical sentence or text grammar to apply fully. Understanding parallels and differences between sentence grammar, text grammar and other cognitive systems is important for the understanding of architecture of grammar itself since it suggests a complex structure consisting out of sentence or text specific abilities and broader abilities.