This article presents a case study on the shifting interaction between clause structure, information structure and discourse organisation in the history of English, as evidenced by the development from Old to Middle English of what we will call discourse particles: discourse-cohesive devices grammaticalised from adverbs. These include the Old English elements þa, þonne, nu, when used in a clause-internal position.We will show that these discourse particles have the following properties: 1) pragmatically: they express the response of the speaker to the context/common ground shared by speaker and hearer, and thus play a pivotal role in common ground management; 2) relation to clause type: the pragmatic meanings of discourse particles are co-determined by the illocutionary force of the clause types in which they occur, including main clause questions, imperatives, hwaet exclamatives, and correlative subclauses; 3) syntactically and information structurally: discourse particles occur in a fixed position in the clause that separates discourse-given from discourse-new information. Discourse particles thus form a subtle lynchpin between pragmatics, discourse management and clause structure.Some particles were lost in the transition to Middle English, but then and now continued to be attested in questions and imperatives, in the same clause-internal position as in OE. Towards the end of the ME period, we see a positional shift to clause-final position, though maintaining the discourse linking character of the particle. This change is due to a syntactic change tightening the use of strict SVO word order and narrowing the use of clause-medial material.