Almost all of chapter 3 of the Aṣṭādhyāyī focuses specifically on the pratyayas (suffixes) that we add directly to a dhātu. These pratyayas come in four main types.
The first type is the sanādi-pratyaya, which creates new dhātus:
गम् + सन् → जिगमिष
gam + san → jigamiṣa
want to go
कृ + णिच् → कारि
kṛ + ṇic → kāri
cause to do or make
The second type is the tiṅ-pratyaya, which creates tiṅantas (verbs):
गम् + तिप् → गच्छति
gam + tip → gacchati
कृ + णल् → चकार
kṛ + ṇal → cakāra
The third type is the vikaraṇa, which we add between a dhātu and the pratyaya that follows it:
भू + शप् + ति → भवति
bhū + śap + ti → bhavati
क्री + श्ना + मि → क्रीणामि
krī + śnā + mi → krīṇāmi
And the fourth type, the kṛt-pratyaya, is any other pratyaya we can add. kṛt-pratyayas create prātipadikas (stems) that eventually become subantas:
युज् + घञ् → योगः
yuj + ghañ → yogaḥ
बुध् + क्त्वा → बुद्ध्वा
budh + ktvā → buddhvā
after waking up
पच् + ण्वुल् → पाचकः
pac + ṇvul → pācakaḥ
In this unit, we will learn about some of common kṛt-pratyayas and understand some of the sandhi changes they cause.
General rules for kṛt-pratyayas
All kṛt-pratyayas are declared within the scope of these four adhikāra rules:
… is a pratyaya (suffix).
… and [it is inserted] after [the base].
After a dhātu, …
… is called kṛt if it is not tiṅ.
Together, these four adhikāra rules mean “… is added as a kṛt-pratyaya after a dhātu, if it is not a tiṅ-pratyaya.”
Further, these two samjñā rules will add extra labels to any pratyaya we introduce within the scope of these rules:
tiṅ and [kṛt-pratyayas that are] śit (i.e. with ś as an it) are called sārvadhātuka.
आर्धधातुकं शेषः। ३.४.११४
ārdhadhātukaṃ śeṣaḥ (3.4.114)
All other [kṛt-pratyayas] are called ārdhadhātuka.
That is, kṛt-pratyayas are generally labeled ārdhadhātuka; but if they have ś as an it letter, they are labeled sārvadhātuka instead.
kṛt-pratyayas cause various sound changes. Generally, they cause guṇa changes by the following rules:
Of an aṅga (the base before a suffix), …
The i of mid [as an aṅga] becomes guṇa.
[The final of an aṅga is replaced with guṇa] when followed by a sārvadhātuka or ārdhadhātuka suffix.
पुगन्तलघूपधस्य च। ७.३.८६
pugantalaghūpadhasya ca (7.3.86)
And [the last ik vowel of an aṅga] ending with pu̐k or whose upadhā (penultimate sound) is laghu (a light syllable) [is replaced with guṇa when followed by a sārvadhātuka or ārdhadhātuka suffix].
But if they have ñ or ṇ as it letters, they can cause vṛddhi changes instead:
The ṛ of mṛj [as an aṅga] becomes vṛddhi.
अचो ञ्णिति। ७.२.११५
aco ñṇiti (7.2.115)
The ac [of an aṅga becomes vṛddhi] if followed by ñit or ṇit.
अत उपधायाः। ७.२.११६
ata upadhāyāḥ (7.2.116)
The penultimate at [of an aṅga becomes vṛddhi if followed by ñit or ṇit].
And as a reminder, guṇa and vṛddhi substitutions are defined only for specific vowels:
इको गुणवृद्धी। १.१.३
iko guṇavṛddhī (1.1.3)
guṇa and vṛddhi replace the ik vowels,
And they are blocked if the pratyaya has k or ṅ as an it letter:
क्ङिति च। १.१.५
kṅiti ca (1.1.5)
but [not] when followed by [terms that are] kit or ṅit.
Sometimes, an i vowel will be added between the dhātu and the pratyaya:
भू + तुम् → भवितुम्
bhū + tum → bhavitum
This i vowel is called iṭ (not to be confused with it, which refers to the “tag” letters on a term in upadeśa). Certain roots use iṭ, certain roots don't, and some roots use it optionally.
The specific rules for using iṭ are complex and detailed, but two rules sum up the general idea. Generally, any ārdhadhātuka suffix that starts with a consonant other than y will use iṭ:
ārdhadhātukasya iṭ val-ādeḥ
[iṭ is added] to an ārdhadhātuka (pratyaya) that starts with val (any consonant other than y).
But if the dhātu has an anudātta accent in its upadeśa form, then iṭ is not used:
एकाच उपदेशेऽनुदात्तात्। ७.२.१०
ekāca upadeśe'nudāttāt (7.2.10)
eka-acaḥ upadeśe anudāttāt
After [a dhātu] that has exactly one vowel and that has an anudātta accent in upadeśa, [iṭ is not used].