7.2.102
त्यदादीनामः
Operational rule vidhi
The words of त्यदादिगण get an अकारादेश when followed by a विभक्तिप्रत्यय.
Word by word (padaccheda)
Target त्यदादीनाम् ṣaṣṭhī · bahuvacanaSubstitute / term अः prathamā · ekavacana
- Target Ṣaṣṭhī (6th case): names what gets replaced, "in place of X" (1.1.49 षष्ठी स्थानेयोगा).
- Substitute / term Prathamā (1st case): in operational rules, the substitute or the thing introduced; in definitions, the term or its referent.
Dotted words are technical terms. Hover or tap one to see its card.
Full reading
त्यदादीनाम् अः
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
त्यदादीनाम् → अः
Replace tyadādīnām with aḥ. Inherited words (anuvṛtti) may add further conditions.
Commentary
For the final of त्यद् etc. there is substituted अ when an affix called विभक्ति follows.
Thus त्यद् - त्यः, त्यौ, त्ये ॥ तद् — सः, तौ, ते; यद् — यः, यौ, ये; एतद् — एषः, एतौ, एते; एदम् — अयम्, इमौ, इमे; अदस् — असौ, अमू, अमी; द्वि, द्वौ, द्वाभ्याम् ॥ The tyadadi words extend upto द्वि, in the list of the pronouns, for the purposes of this अ substitution. Therefore, the substitution does not take place here in भवत् which forms भवान् ॥ When the word त्यद् &c are employed as names, or as a secondary member in a compound, the substitution does not take place, as त्यद्, त्यदौ, त्यदः, अतित्यद्, अतित्यदौ, अतित्यदः See also (l. 1.27) commentary. But when they form the principal member of a compound, the substitution takes place, as परमसः, परमतौ, परमते ॥ For case affix (vibhakti) see 5.3.1 also. Those affixes are also called vibhakti and cause these substitutions.
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.