An adjective is repeated, when it is meant to express that the said attribute belongs to a thing only to a limited degree and the double word is treated like a karmadhāraya samāsa ,
The word प्रकार means both 'difference' and 'resemblance'. It means 'resemblance' here: i.e. the person or thing resembles, but is not fully like, the thing expressing the attribute. Thus पटुपटुः꣡, 'tolerably sharp', मृदुमृदुः꣡ \pretty soft\, पण्डितपण्डितः꣡ &c. The sense is that the attribute is not fully possessed by the person. The affix जातयिर् 5.3.69 also expressing प्रकार, is not debarred by this sutra. Thus पटुजातीयः, मृदुजातीयः ॥
Why do we say prakare \when denoting somewhat like it\? Observe पटुर्देवदत्तः 'the clever Devadatta'. Why do we say 'an attributive or adjective word'? Observe अग्निर्माणवकः, 'a fiery boy', गौर्वाहीकः 'a cow-like Bahika'. Here 'agni' and 'gau' are not naturally adjective words, though employed here like adjectives.
Vart:- An adjective is repeated when denoting that persons or things possessing that attribute are to be taken in their due order. Thus मूले मूले स्थूलाः, अग्रे अग्रे सूक्ष्माः, ज्येष्ठं ज्येष्ठं प्रवेशयः ॥
Vart:- A word denoting more than one is repeated without change of sense, when it denotes the limit or extent of the thing. Thus अस्मात् कार्षापणादिह भवद्भ्यां माषं माषं देहि 'give a masha, a masha out of this karshapana to you two': i. e. give only two masha one to each. A karshapana contains many mashas, out of them, the extent of gift is limited to two only. This therefore is distinguishable from the distributive double (vipsa). The words माषं माषं देहि = द्वौ देहि; the माष does not take the dual case here. Why do we say 'when it expresses the limit'? Observe अस्मात् कार्षापणादिह भवद्भ्यां माषमेकं देहि, द्वौ माषौ देहि, त्रीन्वा माषान् देहि. Here the word माष itself does not express limit, but the qualifying words एकं, द्वौ, त्रीन् &c. Why do we say 'denoting more than one'? Observe अस्मात् कार्षापणादिह भवद्भ्यां माषमेकं देहि ॥
Vart:- In expressing perplexity or alarm, a word may be repeated twice. The word चापल in the vartika means 'a confused state of mind'. As अहिरहिः बुध्यस्व बुध्यस्व 'a snake, a snake, beware. beware'. It is not a necessary condition that the word should be repeated twice only, but as many times as one likes, so long as his meaning is not manifest. As : अहिः अहिः अहिः, बुध्यस्व बुध्यस्व बुध्यस्व ॥
Vart:- When intensity or frequency of an action is denoted, the word is uttered twice: as, स भवान् लुनीहि लुनीहि इत्येवायं लुनाति ॥ See 3.4.2.
Vart:- In re-iteration the word is doubled; as, भुक्त्वा भुक्त्वा व्रजति, भोजं भोजं व्रजति ॥ See 3.4.22. This has also been illustrated under 8.1.4.
Vart:- The word is repeated when the affix डाच् follows; as, पटपटा करोति, पटपटायते ॥ This doubling takes place when the word denotes an imitation of an inarticulate sound 5.4.57. Therefore, not here, द्वितीया करोति, तृतीया करोति, where the affix डाच् denotes 'to plough', 5.4.58. Because of this restriction, some read the vartika as, डाचि बहुलम् ॥
Vart:- The words पूर्व and प्रथम are repeated when a comparative or superlative sense is to be denoted: as पूर्वं पूर्वं पुष्प्यन्ति, प्रथमं प्रथमं पच्यन्ते ॥ The comparative and superlative affixes are not debarred hereby, as, पूर्वतरं पुष्प्यन्ति, प्रथमतरं पच्यन्ते ॥
Vart:- The words ending in the affixes उत्तर and उत्तम (comparative and superlative), are doubled when they refer to feminine nouns and are employed in determining or pondering upon the relative condition of the superiority of one out of two or many; as उभाविमावाढ्यौ, कतरा कतरा अनयोराढ्यता \Both these are rich: let us ponder how much is their richness.\ सर्व इमे आढ्याः, कतमा कतमा एषामाढ्यता ॥ This is found in words other than those ending in तर and तम; as; उभाविमावाढ्यौ, किदृशी किदृशी अनयोराढ्यता ॥ This is also found where the abstract noun denoting condition (as आढ्यता) is not in the feminine: as, उभाविमावाढ्यौ, कतरः कतरोऽनयोर्विभवः \Both these are rich, let us see what is their respective greatness.\
Vart:- In denoting reciprocity of action, the Pronominal is doubled; and diversely it is treated like a compound 2.2.27 when it is not treated like a compound, then the first word is always exhibited in the nominative singular. See 1.3.14, 3.3.43, and 5.4.127. Thus अन्यमन्यमिमे ब्राह्मणा भोजयन्ति \these Brahmanas feed one another.\ अन्योन्यमिमे ब्राह्मणा भोजयन्ति ॥ अन्योऽन्यस्य ब्राह्मणा भोजयन्ति = इतरेतरान् भोजयन्ति ॥ The word अन्य and पर are never treated as a compound, and इतर is always so treated. The following are from Siddhanta Kaumudi:- अन्योऽन्यौ, अन्योऽन्यान् अन्योऽन्येनकृतं, अन्योऽन्यस्मैदत्तं, अन्योऽन्येषां पुष्करैरामृशन्ते (Magh) परस्परं ॥
Vart:- In the feminine and neuter, the augment आम् is added optionally to the second term under the above circumstances, as, अन्योऽन्यामिमे ब्राह्मण्यौ भोजयतः, अन्योऽन्यं भोजयतः, इतरेतरां भोजयतः, इतरेतरं भोजयतः ॥ अन्योऽन्यामिमे ब्राह्मणकुले भोजयतः, इतरेतरामिमे ब्राह्मणकुले भोजयतः, इतरेतरमिमे ब्राह्मणकुले भोजयतः ॥,
