To find linguistics-equivalent of पदसिद्धिप्रक्रियाः, I thought of doing Google-search on “Morphology of words”. And lo ! I hit the nail on its head. I got the following – Morphology is the study of the structure and form of words in a language, including inflection, derivation, and the formation of compounds. At the basic level, words are made of “morphemes.” These are the smallest units of meaning: roots and affixes (prefixes and suffixes).
Taking clue from this detail of morphology related to formation of words, one can say that one view of why to study अष्टाध्यायी would be to understand morphology related to formation of words in Sanskrit.
In Sanskrit the processes of morphology do involve the morphemes – the roots and affixes (prefixes and suffixes).
In Sanskrit roots are of two types – verbal roots धातु-s and nominal roots प्रातिपदिक-s
Prefixes उपसर्ग-s are 22 – प्र। परा। अप। सम्। अनु। अव। निस्। निर्। दुस्। दुर्। वि। आङ्। नि। अधि। अपि। अति। सु। उत् |अभि। प्रति। परि। उप।
In Sanskrit suffixes प्रत्यय-s are many. Some study of प्रत्यय-s can be read at https://grammarofsanskrit.wordpress.com/category/%E0%A4%B5%E0%A5%8D%E0%A4%AF%E0%A4%BE%E0%A4%95%E0%A4%B0%E0%A4%A3%E0%A4%AE%E0%A5%8D/%E0%A4%AA%E0%A5%8D%E0%A4%B0%E0%A4%A4%E0%A5%8D%E0%A4%AF%E0%A4%AF%E0%A4%BE%E0%A4%83/
There are also inflections, derivations and the formation of compounds. These words are grammatical terminologies. Let me check them one by one.
- Inflections – a change in the form of a word (typically the ending) to express a grammatical function or attribute such as tense, mood, person, number, case, and gender. In Sanskrit functions of inflections are served by suffixes प्रत्यय-s only.
- Typically words get grammatical attributes such as tense, mood, person, number by तिङ्-suffixes
- words get grammatical attributes such as number, case, and gender by सुप्-प्रत्यय-s
- Derivations – In Sanskrit derivations are innumerable.
- For example from a verbal root one can derive 12 more उपधातु-s for extended functions such as causative, desiderative, repetitive, etc. Words having attributes of tense, mood, person, number by तिङ्-suffixes can be derived from the उपधातु-s also. Even change of voice can be effected for them.
- One can speak of seven generations for any person, for example प्रपितामहः, पितामहः, पिता, सः, पुत्रः, पौत्रः, प्रपौत्रः Grammatical attributes such as number, case, and gender by सुप्-प्रत्यय-s will apply to all these.
- One can also speak of seven days, 3 days prior to today प्रपरह्यः परह्यः ह्यः today अद्य and three days next श्वः परश्वः प्रपरश्वः Note, these are single words, unlike “day before yesterday” or “day after tomorrow” in English.
Going further, पदसिद्धिप्रक्रियाः include additions आगमाः (such as इडागमः), deletions (लोपाः), substitutions (स्थाने अन्यत्) and modifications (आदेशाः, विकरणाः सन्धयश्च).
Importance and charm of अष्टाध्यायी lies exactly in this that it has set up a grammatical logic to all word-formations and that logic will have to be followed for all time to come if any Sanskrit utterance is to be fit to be called as Sanskrit utterance.