This study presents a comprehensive treatment of determination, based on English, Italian and other Germanic or Romance languages. Determiners are identified as those dependents of a nominal head that determine the type of reference for the Noun Phrase, covering articles as well as demonstrative, possessive, quantitative, cardinal and ordinal determiners. The work also accounts for their absence with self-determining nominals, like proper names and pronouns. The author’s approach is sign-based, as syntactic, semantic and pragmatic aspects of words or phrases are treated in parallel by a grammar with logical constraints. In particular, the Head-driven Phrase Structure Grammar (HPSG) originally proposed by Carl Pollard and Ivan Sag is revised adopting a notion of ‘functor’ which proves ideal for all sorts of determiners.