Most work on determiners has been concerned with purely semantic properties, the occurrence of particular determiners in certain syntactic environments such as existential-there sentences, determiners as heads of phrases (the DP hypothesis, Abney 1987) or quantifier scoping. One question that has not been extensively discussed in the literature is how the various English determiners order with respect to each other. This paper presents a syntactic account of determiner sequencing using a set of nine semantically based features. Each determiner carries with it a set of feature values that represent its properties, and a set of values for the properties of any determiners it may modify. These features also play a crucial role in deciding which determiners can participate in constructions such as the number system, genitives, and partitives, as well as which determiners can be modified by adverbs. This analysis of determiner ordering was developed as part of the XTAG project and is presented within the framework of Feature-Based Tree Adjoining Grammar.