as an indefinite article, and forms of ille (reflecting usage in the Romance languages) as a definite article or even quidam (meaning "a certain one/thing" in Classical Latin) as something like an article. Unlike classical Latin, where esse ("to be") was the only auxiliary verb, medieval Latin writers might use habere ("to have") as an auxiliary, similar to constructions in Germanic and Romance languages. The accusative and infinitive construction in classical Latin was often replaced by a subordinate clause introduced by quod or quia. This is almost identical, for example, to the use of que in similar constructions in French. In every age from the late 8th century onwards, there were learned writers (especially within the Church) who were familiar enough with classical syntax to be aware that these forms and usages were "wrong" and resisted their use. Thus the Latin of a theologian like St Thomas Aquinas or of an erudite clerical historian such as William of Tyre tends to avoid most of the characteristics described above, showing its period in vocabulary and spelling alone; the features listed are much more prominent in the language of lawyers (e.g. the 11th-century English Domesday Book), physicians, technical writers and secular chroniclers. However the use of quod to introduce subordinate clauses was especially pervasive and is found at all levels. Changes in vocabulary, syntax, and grammar Medieval Latin had ceased to be a living language and was instead a scholarly language of the minority of educated men (and a tiny number of women) in medieval Europe, used in official documents more than for everyday communication. This resulted in two major features of Medieval Latin compared with Classical Latin, though when it is compared to the other vernacular languages, Medieval Latin developed very few changes. There are many prose constructions written by authors of this period that can be considered "showing off" a knowledge of Classical or Old Latin by the use of rare or archaic forms and sequences. Though they had not existed together historically, it is common that an author would use grammatical ideas of the two periods Republican and archaic, placing them equally in the same sentence. Also, many undistinguished scholars had limited education in "proper" Latin, or had been influenced in their writings by Vulgar Latin. Word order usually tended towards that of the vernacular language of the author, not the artificial and polished word order of Classical Latin.