On the Divisions of Science
Latin Grammar: Third Declension Adjectives
Sciencie autem naturalis subiectum est corpora mundi secundum quod cadunt in motum, et in quietem, et permutacionem non secundum quod habent numerum, mensuram, et formam, et rotunditatem nec secundum quod partes eorum comparantur aliis, nec secundum quod sunt factura dei altissimi.
Third declension adjectives can often be difficult to recognize because of their similarities to other forms. It is important to be able to recognize third declension adjectives and differentiate them from third declension nouns. Be sure to memorize whether a third declension noun has one ending (potens, potens, potens), two endings (naturalis, naturalis, naturale), or three endings (acer, acris, acre). Decline the third declension adjective fortis, fortis, forte to practice recognizing third declension adjectives in different cases.