P25 · The "done" face, the "facing" face — two "already-finished" machines
Draft · in reviewTeacher notes / sources (students may skip)
Corresponds to: Perry Lesson XXV (§268 perfect active participle -vāṃs + §272 directional adjective -añc) = SKT บทที่ 25 "ศัพท์ที่ลงท้ายด้วย -vāms, -an และ -añc ปัจจัย" (words ending in the suffixes -vāms, -an, and -añc). W14 first half, near the end of the consonant-stem section (P20–P26). Sources: Perry §268 · §272 + word list XXV (backbone paradigm and directional meaning) + SKT 25.1–25.7 (Thai terminology and cognate entries) + Ruppel Ch.35 "Perfect Participles" (covers only -vāṃs — Ruppel's whole book has no chapter on -añc) — comparative notes in 260702-P13-P30-四源挖料. Wherever SKT vols 21–25 and the Perry XXV tables carry OCR noise, the original is not cited (caveat note, same precedent as P16/P17); the añc paradigm is rebuilt from Perry §272's prose rather than copied from an OCR table. No draft base text exists for the consonant-stem unit (07); the story and classroom flow were designed independently by the four-corner team, with all verbs recycled from earlier lessons. Core insight: two "already-finished" machines — the "done" face (-vāṃs: someone/something that has done a thing and is therefore in a certain state, e.g. vidvas "having known" → "learned"), plus the "facing" face (-añc: prefix + añc "facing a direction," e.g. udañc "facing north," tiryañc "walking sideways" → "beast"). Both change bodies via "fat face — thin face," the same mechanism as P24's -vant/-mant. Flagship anchor: the directional words Thai uses every day (อุดร "north," ทักษิณ "south") and today's grammatical directional word (-añc) come from two separate roots — but two -añc words did sneak into Thai: ดิรัจฉาน ("beast" ← tiryañc "walking sideways") and ปราจีน ("east" ← prāc-).
"Bangkok residents see two directional words every day: อุดร ("north") — อุดรธานี Udon Thani province is right there in the north of Thailand; ทักษิณ ("south") — both 'the south' (ทิศทักษิณ) and the surname of that former prime minister.
These two were borrowed from Sanskrit uttara (north) and dakṣiṇa (south). But the directional word you're learning today is a different system entirely: Sanskrit grammar has a 'facing machine' -añc — prāñc "facing east," udañc "facing north," pratyañc "facing west" — a different root from the words Thai uses every day; don't confuse them.
That said, two parts of this añc machine did sneak into Thai: ดิรัจฉาน ("beast") ← tiryañc ("walking sideways"), ปราจีน ("east," as in ปราจีนบุรี province) ← prāc- ("facing east").
And one more star today: วิทวัส ← vidvas ("one who knows, a learned person") — a word made by another machine, the 'done face.'"
This lesson's sound rule (D3, taught alongside the vocabulary): อุดร ← uttara — Sanskrit uttara has a doubled consonant tt (उत्त), and everyday Thai collapses the two into a single ด: อุตฺตร (formal spelling keeps the double) → อุดร (spoken form collapses to a single letter). A doubled consonant collapsing into one = D3. The same witness: อุดม ← uttama (excellent, tt collapses to a single letter, see Decoder Card #94).
(Every verb is recycled: agacchat←P01/P11, apaśyat←P05/P11, apṛcchat←P03/P11, avadat←P01/P11; saḥ←P19 pronoun. Only three new faces: vidvas (knower, this lesson's "done" face), tiryañc (beast, this lesson's "facing" face), plus the word-list items siṃha (lion) / deśa (country) / maghavan (Indra, an -an-family word neighboring P24). All sandhi recycled: ๑ ṛṣir udañcaṃ (iḥ + vowel → ir, the old ṛṣir face from P04/P21), udañcaṃ deśam (m + consonant → ṃ, P02); ๒ sa siṃhaṃ (pronoun saḥ + consonant → sa, the P19 special case), cāpaśyat (ca + a → cā, P02 vowel sandhi); ๓ kumāro vidvāṃsam (aḥ + voiced → o, the P02 rāmo type), kutra maghaveti (ā + i → e, P02 guṇa sandhi, listen only); ๔ agacchad iti (final -t + vowel → -d, the voicing sandhi near P13). Recognition points per sentence: ๑ วิทวัส/ฤๅษี/ประเทศ; ๒ สิงห/เดรัจฉาน; ๓ กุมาร/วิทวัส/มฆวัน; ๔ วิทวัส/มฆวัน/ประเทศ/ปราจีน.)
Line one: the "done" face (-vāṃs, one who has done something).
"New machine: take a verb root meaning 'done,' stick on -vāṃs, and you get the adjective for 'one who has done that thing, and is therefore that kind of person.' Today's showcase word is the easiest to remember — vidvas (√vid "to know," the one and only oddball that doesn't reduplicate and doesn't insert i): having known → learned, a knower. Thai borrowed it whole: วิทวัส.
Just like P24's -vant/-mant, it changes among three bodies:
① Fat face (strong) -vāṃs-: nominative singular drops the s → vidvān; accusative vidvāṃsam, dual vidvāṃsau, nominative plural vidvāṃsaḥ.
② Thinnest face (weakest) -uṣ-: instrumental viduṣā, locative viduṣi, accusative plural viduṣaḥ; feminine viduṣī (declined like nadī, an old hat from P11).
③ Middle face -vat-: neuter nominative/accusative vidvat, before a voiced tail vidvadbhiḥ, locative plural vidvatsu."
vidvas "done"-face full table (this lesson's main table one)
| Case | Masc Sg | Masc Pl | Neut Sg |
|---|---|---|---|
| Nom | विद्वान् vidvān | विद्वांसः vidvāṃsaḥ | विद्वत् vidvat |
| Voc | विद्वन् vidvan | — | विद्वत् vidvat |
| Acc | विद्वांसम् vidvāṃsam | विदुषः viduṣaḥ | विद्वत् vidvat |
| Instr | विदुषा viduṣā | विद्वद्भिः vidvadbhiḥ | (same as masc) |
| Loc | विदुषि viduṣi | विद्वत्सु vidvatsu | (same as masc) |
(Feminine uses the thinnest face + ī: viduṣī विदुषी, the nadī type. Word-formation chain: reduplicated root + vāṃs — cakṛvāṃs "having done" (√kṛ), jagmivāṃs "having gone" (√gam); vidvas is the non-reduplicating exception.)
▸ A point to lighten the load (Ruppel's note): the "done" face is "rarely used," and is being replaced by the -tavant past participle just taught in P24 — so this lesson only asks for recognition, not production. Remembering vidvas's three faces (vidvān→viduṣā→vidvat) is enough to decode it in reading.
Line two: the "facing" face (-añc directional adjective).
"Another machine: prefix + añc (añc's own meaning is 'facing, tilting toward') = 'facing a certain direction.' It's also fat-face/thin-face shape-shifting — the fat face keeps -añc-, the thin face shrinks to -ac-, and the thinnest one even sprouts an ī (→ -īc-)."
añc "facing"-face small table (rebuilt from Perry §272, this lesson's main table two)
| Word (prefix + añc) | Facing where | Fat face (strong) | Middle face | Thinnest face |
|---|---|---|---|---|
| prāñc (pra-) | front / east | प्राञ्च् prāñc | प्राच् prāc | प्राच् prāc |
| pratyañc (prati-) | back / west | प्रत्यञ्च् pratyañc | प्रत्यच् pratyac | प्रतीच् pratīc |
| udañc (ud-) | up / north | उदञ्च् udañc | उदच् udac | उदीच् udīc |
| avāñc (ava-) | down / south | अवाञ्च् avāñc | — | अवाच् avāc |
| tiryañc (tiras-) | sideways → beast | तिर्यञ्च् tiryañc | तिर्यच् tiryac | तिरश्च् tiraśc |
(The direction nouns use the thinnest face + ī, as feminines, declined like nadī: prācī "east," pratīcī "west," udīcī "north" — locatives prācyām／pratīcyām／udīcyām "in the east/west/north." This thin face prāc- is precisely where Thai ปราจีน [prāc-īna, "east"] comes from; the meaning "sideways-walking beast" of tiryañc is exactly Thai ดิรัจฉาน [beast].)
The two directional systems — don't mix them (flagship comparison):
"The eight directions Thai uses every day — อุดร (uttara, north) / บูรพา (pūrva, east) / ทักษิณ (dakṣiṇa, south) / ประจิม (paścima, west) — belong to an entirely separate set of roots, not products of the añc machine. The añc machine (prāñc/udañc…) is a grammatical directional adjective. The two systems each go their own way; only ดิรัจฉาน and ปราจีน are two words that leaked into Thai from the añc side."
Building blocks: no new building blocks this lesson.
TPRS wrap-up: "Which direction did the seer go? What did he see there? What did the boy ask? Which direction did Indra go?" — students answer using udañcam／prāñcam／tiryañcam, choral recitation of the four-sentence sandhi version.
- "'Done' face -vāṃs = 'one who has done something,' three bodies: fat -vāṃs- (vidvān/vidvāṃsam) / thin -uṣ- (viduṣā/viduṣī) / middle -vat- (vidvat/vidvatsu) — the same shape-shifting logic as P24's -vant, recognition only."
- "vidvas is the oddball showcase word: √vid 'to know' doesn't reduplicate, doesn't insert i, straight to vidvān 'the knower' — being that odd is exactly what makes it easy to remember."
- "'Facing' face -añc = prefix + añc, 'facing a certain direction': prāñc east, udañc north, pratyañc west, tiryañc sideways (→ beast); fat -añc- / thin -ac- (thinnest sprouts ī → -īc-)."
- "Sound-rule day D3: Sanskrit's doubled consonant collapses into one — uttara's tt → อุดร (that's how อุดรธานี province is spelled); uttama → อุดม, same pattern."
vidvas three-faces in a row: 🔇vidvān↔viduṣā🔇↔vidvat (fat→thin→middle, guards against confusion); feminine viduṣī read slowly (nadī hat); word-formation chain: 🔇cakṛvāṃs↔jagmivāṃs🔇 (reduplicated root + vāṃs), compared against the non-reduplicating vidvas; añc face-change slices: 🔇udañc↔udīc🔇, 🔇pratyañc↔pratīc🔇, 🔇tiryañc↔tiraśc🔇 (fat face ↔ thinnest face, listen for the ī sprouting out); direction feminines: prācī／pratīcī／udīcī (east, west, north, nadī type); four story sentences in both versions; sandhi slices: ṛṣir udañcaṃ (the ir old face) / sa siṃhaṃ (saḥ→sa) / kumāro vidvāṃsam / agacchad iti. Recognition reading of a classic verse (Perry §XXV exercise 13, an OCR-clear passage): vidvān praśasyate loke "the wise one is praised in the world" — used only as a recognition demonstration of -vāṃs.
(Teacher-reference words: maghavan มฆวัน/มัฆวา (Indra, an -an-family word, the P24 paradigm; Perry XXV word list), pariṣad บริษัท (assembly → company, semantic drift), deśa/pradeśa ประเทศ (country), jagat ชัค/ชคัต (world, literary register), uttara อุดร・pūrva บูรพา・dakṣiṇa ทักษิณ・paścima ประจิม (the other set of directional roots, for comparison, see CSV line 860's ทศทิศ "ten directions" entry), prācīna ปราจีน (east, a derivative of the thin face prāc-); yuvan (youth)／ahan (day)／śvan (dog) etc., -an special stems, belong to P24, not repeated here; takṣaśilā (Takṣaśilā, a place name in Perry's word list, grep confirms it's not in the CSV — no hook is built where none exists, used only as a recognition-level place name.)
The next crystallization lesson (the full P20–P26 consonant-stem review): the "done" face vidvas and the "facing" face añc line up together — alongside P24's -vant/-mant and the -an family (maghavan/yuvan/śvan) in the same row, showing how "fat face — thin face — middle face," a three-tier body change, is the unified logic of consonant stems; the direction feminines prācī/pratīcī/udīcī (nadī type) are folded into the feminine quick-reference card; the samprasāraṇa of añc's thinnest face (ya→ī: pratyañc→pratīc) is treated as an advanced-recognition item — the student page just says "an ī sprouts out."