Over the past decades it has become generally acknowledged that lexicon and grammar are inseparably linked, constituting “a continuum of symbolic structures“ (Langacker 1990:2). Yet, a comprehensive integration of the two realms of knowledge appears to be a difficult task. The present article offers a unified psycholinguistic perspective, which is centred on the mental lexicon, considering grammatical knowledge as part of the information structure of lexical items. It aims to model the complexity of lexical knowledge such that its perceived psychological reality, including various levels of linguistic description, becomes discernible.