phonological segments, lexical items and the grammar for the Classical Sanskrit consist of four Paninian components. These, states Paul Kiparsky, are the Astadhyaayi, a comprehensive system of 4,000 grammatical rules, of which a small set are frequently used; Sivasutras, an inventory of anubandhas (markers) that partition phonological segments for efficient abbreviations through the pratyharas technique; Dhatupatha, a list of 2,000 verbal roots classified by their morphology and syntactic properties using diacritic markers, a structure that guides its writing systems; and, the Ganapatha, an inventory of word groups, classes of lexical systems. There are peripheral adjuncts to these four, such as the Unadisutras, which focus on irregularly formed derivatives from the roots. Sanskrit morphology is generally studied in two broad fundamental categories: the nominal forms and the verbal forms. These differ in the types of endings and what these endings mark in the grammatical context. Pronouns and nouns share the same grammatical categories, though they may differ in inflection. Verb-based adjectives and participles are not formally distinct from nouns. Adverbs are typically frozen case forms of adjectives, states Jamison, and "nonfinite verbal forms such as infinitives and gerunds also clearly show frozen nominal case endings". Tense and voice The Sanskrit language includes five tenses: present, future, past imperfect, past aorist and past perfect. It outlines three types of voices: active, passive and the middle. The middle is also referred to as the mediopassive, or more formally in Sanskrit as (word for another) and (word for oneself). The paradigm for the tense-aspect system in Sanskrit is the three-way contrast between the "present", the "aorist" and the "perfect" architecture. Vedic Sanskrit is more elaborate and had several additional tenses. For example, the Rigveda includes perfect and a marginal pluperfect. Classical Sanskrit simplifies the "present" system down to two tenses, the perfect and the imperfect, while the "aorist" stems retain the aorist tense and the "perfect" stems retain the perfect and marginal pluperfect. The classical version of the language has elaborate rules for both voice and the tense-aspect system to emphasize clarity, and this is more elaborate than in other Indo-European languages. The evolution of these systems can be seen from the earliest layers of the Vedic literature to the late Vedic literature. Number, person Sanskrit recognizes three numbers—singular, dual, and plural. The dual is a fully functioning category, used beyond naturally paired objects such as hands or eyes, extending to any collection of