ភាសាបាលី: គីតសទ្ទោ

គីតសទ្ទោ 
Although Pali cannot be considered a direct descendant of either Classical Sanskrit or of the older Vedic dialect , the languages are obviously very closely related and the common characteristics of Pali and Sanskrit were always easily recognized by those in India who were familiar with both.  Indeed, a very large proportion of Pali and Sanskrit word-stems are identical in form, differing only in details of inflection.

The connections were sufficiently well-known that technical terms from Sanskrit were easily converted into Pali by a set of conventional phonological transformations.  These transformations mimicked a subset of the phonological developments that had occurred in Proto-Pali.  Because of the prevalence of these transformations, it is not always possible to tell whether a given Pali word is a part of the old Prakrit lexicon, or a transformed borrowing from Sanskrit.  The existence of a Sanskrit word regularly corresponding to a Pali word is not always secure evidence of the Pali etymology, since, in some cases, artificial Sanskrit words were created by back-formation from Prakrit words.

The following phonological processes are not intended as an exhaustive description of the historical changes which produced Pali from its Old Indic ancestor, but rather are a summary of the most common phonological equations between Sanskrit and Pali, with no claim to completeness.

 ស្រៈ និង ស្រៈផ្សំ 
Sanskrit ai and au always monophthongize to Pali e and o, respectively
Examples: maitrī → mettā, auṣadha → osadha
Sanskrit aya and ava likewise often reduce to Pali e and o
Examples: dhārayati → dhāreti, avatāra → otāra, bhavati → hoti
Sanskrit avi becomes Pali e (i.e. avi → ai → e)
Example: sthavira → thera
Sanskrit ṛ appears in Pali as a, i or u, often agreeing with the vowel in the following syllable. ṛ also sometimes becomes u after labial consonants.
Examples: kṛta → kata, tṛṣṇa → taṇha, smṛti → sati, ṛṣi → isi,  dṛṣṭi → diṭṭhi, ṛddhi → iddhi, ṛju → uju, spṛṣṭa → phuṭṭha, vṛddha → vuddha

Sanskrit long vowels are shortened before a sequence of two following consonants.
Examples: kṣānti → khanti, rājya → rajja, īśvara → issara, tīrṇa → tiṇṇa,  pūrva → pubba

 ព្យញ្ជនៈ 
 បម្រែបម្រួលសម្លេង 
The Sanskrit sibilants ś, ṣ, and s merge together as Pali s
Examples: śaraṇa → saraṇa, doṣa → dosa
The Sanskrit stops ḍ and ḍh become ḷ and ḷh between vowels (as in Vedic)
Example: cakravāḍa → cakkavāḷa, virūḍha → virūḷha

 Assimilations 
 ក្បួនច្បាប់ទូទៅ 
Many assimilations of one consonant to a neighboring consonant occurred in the development of Pali, producing a large number of geminate (double) consonants. Since aspiration of a geminate consonant is only phonetically detectable on the last consonant of a cluster, geminate kh, gh, ch, jh, ṭh, ḍh, th, dh, ph and bh appear as kkh, ggh, cch, jjh, ṭṭh, ḍḍh, tth, ddh, pph and bbh, not as khkh, ghgh etc.
When assimilation would produce a geminate consonant (or a sequence of unaspirated stop+aspirated stop) at the beginning of a word, the initial geminate is simplified to a single consonant.
Examples: prāṇa → pāṇa (not ppāṇa), sthavira → thera (not tthera), dhyāna → jhāna (not jjhāna), jñāti → ñāti (not ññāti)
When assimilation would produce a sequence of three consonants in the middle of a word, geminates are simplified until there are only two consonants in sequence.
Examples: uttrāsa → uttāsa (not utttāsa), mantra → manta (not mantta), indra → inda (not indda), vandhya → vañjha (not vañjjha)
The sequence vv resulting from assimilation changes to bb
Example: sarva → savva → sabba, pravrajati → pavvajati → pabbajati, divya → divva → dibba

 Total assimilation 
Total assimilation, where one sound becomes identical to a neighboring sound, is of two types: progressive, where the assimilated sound becomes identical to the following sound; and regressive, where it becomes identical to the preceding sound.

 Progressive assimilations 
Internal visarga assimilates to a following voiceless stop or sibilant
Examples: duḥkṛta → dukkata, duḥkha → dukkha, duḥprajña → duppañña, niḥkrodha (=niṣkrodha) → nikkodha, niḥpakva (=niṣpakva) → nippakka, niḥśoka → nissoka, niḥsattva → nissatta
In a sequence of two dissimilar Sanskrit stops, the first stop assimilates to the second stop
Examples: vimukti → vimutti, dugdha → duddha, utpāda → uppāda, pudgala → puggala, udghoṣa → ugghosa, adbhuta → abbhuta, śabda → sadda
In a sequence of two dissimilar nasals, the first nasal assimilates to the second nasal
Example: unmatta → ummatta, pradyumna → pajjunna
j assimilates to a following ñ (i.e., jñ becomes ññ)
Examples: prajñā → paññā, jñāti → ñāti
The Sanskrit liquid consonants r and l assimilate to a following stop, nasal, sibilant, or v
Examples: mārga → magga, karma → kamma, varṣa → vassa, kalpa → kappa, sarva → savva → sabba
r assimilates to a following l
Examples: durlabha → dullabha, nirlopa → nillopa
d sometimes assimilates to a following v, producing vv → bb
Examples: udvigna → uvvigga → ubbigga, dvādaśa → bārasa (beside dvādasa)
t and d may assimilate to a following s or y when a morpheme boundary intervenes
Examples: ut+sava → ussava, ud+yāna → uyyāna

 Regressive assimilations 
Nasals sometimes assimilate to a preceding stop (in other cases epenthesis occurs; see below)
Examples: agni → aggi, ātman → atta, prāpnoti → pappoti, śaknoti → sakkoti
m assimilates to an initial sibilant
Examples: smarati → sarati, smṛti → sati
Nasals assimilate to a preceding stop+sibilant cluster, which then develops in the same way as such clusters without following nasals (see Partial assimilations below)
Examples: tīkṣṇa → tikṣa → tikkha, lakṣmī → lakṣī →lakkhī
The Sanskrit liquid consonants r and l assimilate to a preceding stop, nasal, sibilant, or v
Examples: prāṇa → pāṇa, grāma → gāma,  śrāvaka → sāvaka, agra → agga, indra → inda, pravrajati → pavvajati → pabbajati, aśru → assu
y assimilates to preceding non-dental/retroflex stops or nasals
Examples: cyavati → cavati, jyotiṣ → joti, rājya → rajja, matsya → macchya → maccha, lapsyate → lacchyate → lacchati, abhyāgata → abbhāgata, ākhyāti → akkhāti, saṁkhyā → saṅkhā (but also saṅkhyā), ramya → ramma
y assimilates to preceding non-initial v, producing vv → bb
Example: divya → divva → dibba, veditavya → veditavva → veditabba, bhāvya → bhavva → bhabba
y and v assimilate to any preceding sibilant, producing ss
Examples: paśyati → passati, śyena → sena, aśva → assa, īśvara → issara, kariṣyati → karissati, tasya → tassa, svāmin → sāmī
v sometimes assimilates to a preceding stop
Examples: pakva → pakka, catvāri → cattāri, sattva → satta, dhvaja → dhaja

 Partial and mutual assimilation 
Sanskrit sibilants before a stop assimilate to that stop, and if that stop is not already aspirated, it becomes aspirated; e.g. śc, st,  ṣṭ and sp become cch, tth, ṭṭh and pph
Examples: paścāt → pacchā, asti → atthi, stava → thava, śreṣṭha → seṭṭha, aṣṭa → aṭṭha, sparśa → phassa
In sibilant-stop-liquid sequences, the liquid is assimilated to the preceding consonant, and the cluster behaves like sibilant-stop sequences; e.g. str and ṣṭr become tth and ṭṭh
Examples: śāstra → śasta → sattha, rāṣṭra → raṣṭa → raṭṭha
t and p become c before s, and the sibilant assimilates to the preceding sound as an aspirate (i.e., the sequences ts and ps become cch)
Examples: vatsa → vaccha, apsaras → accharā
A sibilant assimilates to a preceding k as an aspirate (i.e., the sequence kṣ becomes kkh)
Examples: bhikṣu → bhikkhu, kṣānti → khanti
Any dental or retroflex stop or nasal followed by y converts to the corresponding palatal sound, and the y assimilates to this new consonant, i.e. ty, thy, dy, dhy, ny become cc, cch, jj, jjh, ññ; likewise ṇy becomes ññ.  Nasals preceding a stop that becomes palatal share this change.
Examples: tyajati → cyajati → cajati, satya → sacya → sacca, mithyā →  michyā → micchā, vidyā → vijyā →  vijjā, madhya → majhya → majjha, anya → añya → añña, puṇya → puñya → puñña, vandhya →  vañjhya → vañjjha → vañjha
The sequence mr becomes mb, via the epenthesis of a stop between the nasal and liquid, followed by assimilation of the liquid to the stop and subsequent simplification of the resulting geminate.
Examples: āmra → ambra → amba, tāmra → tamba

 Epenthesis 
An epenthetic vowel is sometimes inserted between certain consonant-sequences.  As with ṛ, the vowel may be a, i, or u, depending on the influence of a neighboring consonant or of the vowel in the following syllable. i is often found near i, y, or palatal consonants; u is found near u, v, or labial consonants.
Sequences of stop + nasal are sometimes separated by a or u
Example: ratna → ratana, padma → paduma (u influenced by labial m)
The sequence sn may become sin initially
Examples: snāna → sināna, sneha → sineha
i may be inserted between a consonant and l
Examples: kleśa → kilesa, glāna → gilāna, mlāyati → milāyati, ślāghati → silāghati
An epenthetic vowel may be inserted between an initial sibilant and r
Example: śrī → sirī
The sequence ry generally becomes riy (i influenced by following y), but is still treated as a two-consonant sequence for the purposes of vowel-shortening
Example: ārya → arya → ariya, sūrya → surya → suriya, vīrya → virya → viriya
a or i is inserted between r and h
Example: arhati → arahati, garhā → garahā, barhiṣ → barihisa
There is sporadic epenthesis between other consonant sequences
Examples: caitya → cetiya (not cecca), vajra → vajira (not vajja)

 Other changes 
Any Sanskrit sibilant before a nasal becomes a sequence of nasal followed by h, i.e. ṣṇ, sn and sm become ṇh, nh, and mh
Examples: tṛṣṇa → taṇha, uṣṇīṣa → uṇhīsa, asmi → amhi
The sequence śn becomes ñh, due to assimilation of the n to the preceding palatal sibilant
Example: praśna → praśña → pañha
The sequences hy and hv undergo metathesis
Examples: jihvā → jivhā, gṛhya → gayha, guhya → guyha
h undergoes metathesis with a following nasal
Example: gṛhṇāti → gaṇhāti
y is geminated between e and a vowel
Examples: śreyas → seyya, Maitreya → Metteyya

Voiced aspirates such as bh and gh on rare occasions become h
Examples: bhavati → hoti, -ebhiṣ → -ehi, laghu → lahu
Dental and retroflex sounds sporadically change into one another
 Examples: jñāna → ñāṇa (not ñāna), dahati → ḍahati (beside Pali dahati) nīḍa → nīla (not nīḷa), sthāna → ṭhāna (not thāna), duḥkṛta → dukkaṭa (beside Pali dukkata)

 Excptions 
There are several notable exceptions to the rules above; many of them are common Prakrit words rather than borrowings from Sanskrit.
ārya → ayya (beside ariya)
guru → garu (adj.) (beside guru (n.))
puruṣa → purisa (not purusa)
vṛkṣa → rukṣa → rukkha (not vakkha)