Modal particles and their same-form counterparts in other parts of speech display heterosemic relations (cross-category semantic relations). Comparison of the lexemes studied shows that there are class-specific grammaticalization patterns for modal particles. In the framework of a modular-oriented theory of meaning, the combination of synchronic and diachronic analysis produces minimalist meaning postulates for non-propositional usage. The Old/Middle/early New High German e(cher)t is a hitherto undiscovered modal particle that went out of currency in the early stages of New High German.