To conceptualize the communicative role of working memory (WM), the Ease-of-Language Understanding (ELU) model was proposed (e.g., Rönnberg, 2003; Rönnberg et al., 2008, 2013, 2019, 2020). The model states that ease of language understanding is determined by the speed and accuracy with which the signal is matched to existing multimodal language representations. When matching is fast and complete, language understanding is effortless; this process may be facilitated by predictions based on the contents of WM. However, when the contents of the language signal mismatches with existing representations, WM is triggered to access knowledge in semantic long-term memory (SLTM) and personal experience from episodic long-term memory (ELTM) – promoting inference-making and postdictions in WM. The interplay between WM and LTM is fundamental to language understanding; its efficiency becomes apparent in adverse conditions and its breakdown may explain cognitive decline and dementia. Empirical support, limitations, and future studies will be discussed.