I consider preposition-determiner contractions in various European languages and offer a uniform approach using optimality-theoretic Lexical-Functional Grammar with lexical sharing. Lexical sharing allows a preposition and a determiner to share a contraction, which is a single word; this predicts that contractions are disallowed if anything intervenes between the preposition and determiner. Constraints on the syntactic relationship between the preposition and determiner are handled with the mechanisms of Lexical-Functional Grammar. Optimality-theoretic constraints predict when contractions are required in place of independent prepositions and determiners and when they are not. I suggest that this combination of mechanisms may be useful in tackling phenomena beyond preposition-determiner contractions.