We describe a new approach to syntactic generation with Head-Driven Phrase Structure Grammars (HPSG) that uses an extensive off-line preprocessing step. Direct generation algo-• rithms apply the phra~se-structure rules (schemata) of the grammar on:line which is an computationally expensive step. Instead, we collect off-line for every lexical type of the HPSG grammar all minimally complete projections (called elementary trees) that can be derived with the schemata. This process is known as

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... ling HPSG to TAG' and derives a Lexicalized Tree-Adjoining Grammar (LTAG). The representation as an LTAG is 'fully lexicalized' in the sense that all grammatical information is directly encoded with the lexical item (as a set of elementary trees) and the combination operations are reduced from schema applications to the TAG primitives of adjunction and substitution. Given this LTAG, the generation task has a very different search space that Can be traversed very efficiently, avoiding the costly on-line applications of HPSG unification. The entire generation task from a semantic representation to a surface string is split into two tasks, a microplanner and a syntactic realizer. This paper discusses the syntactic generator and the preprocessing steps as implemented in the Verbmobil system.