P20 · The consonant family opens for business: only one gatekeeper stays at the door, bare verb roots serve double duty as nouns
Draft · in reviewTeacher notes / sources (students may skip)
Corresponds to: Perry Lesson XX (§237–245) = SKT บทที่ 20 (general rules for consonant stems §20.1–20.10). Second half of W11. Sources: Perry §237–245 (backbone; this lesson's title is missing its Roman numeral in the OCR, only "## Lesson" survives; the lesson number XX is inferred from its position relative to neighboring lessons and §237's starting point) + Goldman §20.6.a (root-noun / kvip zero-suffix mechanism) + Goldman §21.0–21.1 (three-gender consonant-stem paradigms vāc/śastrabhṛt/viśvasṛj) —— four-source mining in 260702-P13-P30-四源挖料. This lesson has no source draft for unit 07; the four-corner team assembled the material independently (same approach as P15/P18); SKT_Thai vols. 16–20 OCR corrupted, no original-text quotation (same approach as P16/P17). Core: two things — the "three general rules" of consonant stems (the tail's single gatekeeper／the bh-family's four heavy tails' external sandhi／two postures), + root nouns "on duty bare-bodied" (a verb's bare root serving directly as a noun without a suffix — roots you already know, moonlighting today). This week's session has no crystallization lesson (W11 = —); this lesson's skeleton flows into Crystallization Lesson Six (W12, Consonant Stems I).
"Today we open a new family — the consonant family (words whose stem ends in a consonant). Let's first claim three members that Thai uses every day:
ราช ← Sanskrit राช (rāja, king) — its 'bare-bodied' relative is this lesson's rāj／samrāj (sovereign), the same root √rāj (to rule/shine).
วาจา ← Sanskrit वाचा (vācā, speech) — this lesson teaches exactly its bare root vāc, which turns into vāk at the end of a sentence (c→k! you'll see this shortly).
บริษัท (company) ← Sanskrit परिषद् (pariṣad, assembly) — a -ṣad-ending consonant word, the same kind of ending as this lesson's word-list item อุปนิษัท (upaniṣad, the Upaniṣads).
Let's claim one more: ภูมิ… wait — actually let's claim ราชา standing at attention: every day when you say 'I work at a บริษัท,' you're using the drill-stance form of a Sanskrit consonant word, pariṣat (d→t)."
No new Decoder rule this lesson (the rule pool is winding down, mostly review): this lesson's sound-changes all happen inside Sanskrit itself (the tail consonant getting undressed: vāc→vāk, rāj→rāṭ, āpad→āpat), not a new Thai transliteration rule. This is a perfect moment to review P01's C5/A6 "write voiced, read voiceless" — by the time a Sanskrit word reaches its tail, voiced and aspirated sounds all get demoted to plain voiceless, the exact same instinct as Thai's ตัวสะกด (final consonant) only allowing a few sounds at the end of a syllable: standing at the door, everyone has to put on the plainest uniform.
(Six consonant stems, many hats rotating through: bhūbhṛt (king) subject bhūbhṛt／genitive bhūbhṛtaḥ; sarit (river) direction-hat saritam／location-hat sariti; marut (winds) subject-plural marutaḥ／instrument-plural marudbhiḥ (t→d); āpad (danger) subject āpat (d→t); vāc (speech) subject vāk (c→k); suhṛd (close friend) subject suhṛt (d→t). All verbs recycled: agacchat/āgacchan/abhavat←P11, amodata←P08+P13 (Ā-coat past); āgacchan's switch is hidden inside the prefix (ā＋a→ā, recycled from P11's upāviśat trick). All sandhi is a live sweep of old rules: maruta āgacchan (visarga drops before a vowel), sarity āpad (i→y＋t→d, P04), bhūbhṛto vāk (as→o, P02), so 'gacchat (P02's saḥ＋a→so '). Recognition points per sentence: ๑ ราช-root (Thai: "king")／สริต (Thai: "river"); ๒ มรุต (Thai: "wind")／สริต; ๓ ราช-root／วาจา; ๔ สุหฤท (Thai: "close friend")／มรุต.)
Line one: the consonant family's three general rules (mnemonic images).
"Rule one — the tail's gatekeeper (Perry §239／SKT 20.3). When a consonant word stands at the end of a sentence (wearing its subject hat and on drill-stance) or meets a hat beginning with a consonant,
only one consonant is allowed to guard the gate, and it must put on the plainest possible uniform: voiced becomes voiceless, aspirated becomes unaspirated, palatals (c/j) and h always become k or ṭ.
So vāc→vāk (c→k), samrāj→samrāṭ (j→ṭ), āpad→āpat (d→t), suhṛd→suhṛt (d→t).
marut is already a plain unaspirated t, so it doesn't need to change uniform when standing at attention."
"Rule two — the bh-family's four tails = external sandhi (Perry §241／SKT 20.5). Once one of the four 'heavy tails' bhyām／bhis／bhyas／su
attaches, the stem's ending treats itself as a complete word and greets the tail according to the same rules as P02's external sandhi:
marut＋bhis→marudbhiḥ (t before voiced bh becomes d), marut＋su→marutsu (t unchanged before voiceless s), vāc＋bhis→vāgbhiḥ (k's voiced form g).
You already learned this back in P02, it's just being used in a new place."
"Rule three — two postures: chest-out and tucked-in (Perry §238／SKT 20.1). Some consonant words have two body shapes, chest-out and tucked-in, switching depending on which hat they wear.
This lesson's marut／āpad／jagat are the best-behaved single-stem words — one shape from start to finish, only the tail gatekeeper changes.
The real 'posture-switching drama' (-in, -vant, -añc) is saved for later lessons; today, just learn to recognize the faces."
Single-stem three-gender paradigm (Perry §243, marut m.／āpad f.／jagat n. — pending Heritage machine-check)
| masc. marut (wind) | fem. āpad (danger) | neut. jagat (world) | |
|---|---|---|---|
| Subj./Voc. sg. | मरुत् marut | आपत् āpat | जगत् jagat |
| Direction (Acc.) sg. | मरुतम् marutam | आपदम् āpadam | जगत् jagat |
| Instrument sg. | मरुता marutā | आपदा āpadā | जगता jagatā |
| Location sg. | मरुति maruti | आपदि āpadi | जगति jagati |
| Subj./Voc. pl. | मरुतः marutaḥ | आपदः āpadaḥ | जगन्ति jaganti |
| Instrument pl. | मरुद्भिः marudbhiḥ | आपद्भिः āpadbhiḥ | जगद्भिः jagadbhiḥ |
| Location pl. | मरुत्सु marutsu | आपत्सु āpatsu | जगत्सु jagatsu |
"Neuter special note: neuter consonant words like to insert a nasal n into their subject/direction hats in the plural — jagat→jaganti (worlds).
Single-stem three-gender forms differ only in the subject/direction hats, sharing everything else — one set of rules for all three genders."
Line two: bare verb roots — on duty bare-bodied (Goldman §20.6.a).
"A verb's bare root, without any suffix, goes to work directly as a noun. You already know these roots' verb-faces:
√vac (speak) → vāc f. 'speech' (a relative of vadati; Thai วาจา)
√rāj (rule/shine) → samrāj／rāj 'sovereign' (the bare-bodied relative of Thai ราช, drill-stance form samrāṭ)
√bhṛ (bear) → compound tail -bhṛt 'the one who bears…': bhūbhṛt (earth-bearer = mountain/king), śastrabhṛt (weapon-bearer = warrior)
√ji (conquer) → compound tail -jit: indrajit (conqueror of Indra).
The bare root inside a compound usually means 'the one who does this,' with gender following whatever it modifies.
The key point: no suffix doesn't mean no grammar — it's a perfectly regular 'root→noun' conversion, don't mistake it for an irregular word."
Building blocks (used first, analyzed later — this lesson's set): api (also/even) ／ paścāt (after…, takes the genitive hat — the rāmasya paścāt pattern) — two high-frequency indeclinables, used before analysis outside the story.
TPRS wrap-up: "Where did the king go? What happened when the winds came? How was the king's speech? What finally happened to the close friend?" — students retell using the consonant family's various hats.
- "The tail's gatekeeper: only one consonant stays at the sentence's end, and it undresses (voiced→voiceless, aspirated→unaspirated, c/j/h→k/ṭ) — vāk／āpat／suhṛt／samrāṭ."
- "The bh-family's four tails (bhyām/bhis/bhyas/su) = external-sandhi day: marudbhiḥ (t→d)／marutsu (t unchanged)／vāgbhiḥ (k→g) — P02 replayed in a new location."
- "On duty bare-bodied: a bare root goes to work as a noun without a suffix (vāc←√vac, -bhṛt←√bhṛ, -jit←√ji); compound tails usually mean 'the one who…'."
- "Neuter inserts a nasal: neuter consonant words like to insert an n into their subject/direction plural — jagat→jaganti (worlds); single-stem three genders differ only in the subject/direction hats, sharing the rest."
Story's four sentences in both versions; tail-undressing contrast clips: 🔇vāc↔vāk🔇／🔇āpad↔āpat🔇／🔇suhṛd↔suhṛt🔇／🔇samrāj↔samrāṭ🔇 (stem-body vs. drill-stance body, each read slowly); the bh-family's four tails, three in a row: marudbhiḥ (t→d)／marutsu (t unchanged)／vāgbhiḥ (k→g) — lined up with P02's external sandhi for ear-training; neuter nasal-insertion jagat→jaganti slow reading; sandhi clips: bhūbhṛto vāk (as→o)／sarity āpad (i→y＋t→d)／so 'gacchat (recycled from P02), three examples side by side.
(Teacher-reference words: upaniṣad อุปนิษัท (the Upaniṣads, a -ṣad consonant word), pariṣad บริษัท/ปริษัท (assembly→company), śarad สารท/ศรัท (autumn; the วันสารท festival), śata ศต (hundred; ศตวรรษ century), samidh (kindling), bhūbhṛt／nṛpa (alternate names for "king") — Perry XX/SKT 20 word-list items, reserved for decode-and-reclaim and sentence-building. Verbs ruh (rohati, grow / causative rohayati, plant), labh's causative lambhayati — word-list causatives, reserved for formal claiming in the P18 causative line.)
W11 itself has no crystallization lesson (the pacing chart shows —). This lesson's skeleton flows into Crystallization Lesson Six (W12, covering P18–21: causative + pronoun paradigm cluster + Consonant Stems I): "the tail's gatekeeper + pada-ending external sandhi" gets registered alongside the pronoun paradigms and the causative; single-stem three genders (marut/āpad/jagat) + root nouns (vāc/rāj/bhūbhṛt) form the skeleton of Consonant Stems I. The "posture-switching drama" of strong/weak stems (-in/-vant/-añc) is saved for P22–P25, entering Crystallization Lesson Seven (the full panorama of consonant stems) later.