used for the indefinite article "a, an". Use of reflexives became much looser. A reflexive pronoun in a subordinate clause might refer to the subject of the main clause. The reflexive possessive suus might be used in place of a possessive genitive such as eius. Comparison of adjectives changed somewhat. The comparative form was sometimes used with positive or superlative meaning. Also, the adverb "magis" was often used with a positive adjective to indicate a comparative meaning, and multum and nimis could be used with a positive form of adjective to give a superlative meaning. Classical Latin used the ablative absolute, but as stated above, in Medieval Latin examples of nominative absolute or accusative absolute may be found. This was a point of difference between the ecclesiastical Latin of the clergy and the "Vulgar Latin" of the laity, which existed alongside it. The educated clergy mostly knew that traditional Latin did not use the nominative or accusative case in such constructions, but only the ablative case. These constructions are observed in the medieval era, but they are changes that developed among the uneducated commoners. Classical Latin does not distinguish progressive action in the present tense, thus laudo can mean either "I praise" or "I am praising". In imitation of Greek, Medieval Latin could use a present participle with sum to form a periphrastic tense equivalent to the English progressive. This "Greek Periphrastic Tense" formation could also be done in the past and future tenses: laudans sum ("I am praising"), laudans eram ("I was praising"), laudans ero ("I shall be praising"). Classical Latin verbs had at most two voices, active and passive, but Greek (the original language of the New Testament) had an additional "middle voice" (or reflexive voice). One use was to express when the subject is acting upon itself: "Achilles put the armor onto himself" or "Jesus clothed himself in the robe" would use the middle voice. Because Latin had no middle voice, Medieval Latin expresses such sentences by putting the verb in the passive voice form, but the conceptual meaning is active (similar to Latin deponent verbs). For example, the Medieval Latin translation of Genesis states literally, "the Spirit of God was moved over the waters" ("spiritus Dei ferebatur super aquas", Genesis 1:2), but it is just expressing a Greek middle-voice verb: "God moved [himself] over the waters". Overlapping with orthography differences (see below), certain diphthongs were sometimes