The two affixes beginning with a vowel i.e. īyas and iṣṭha are added only after words denoting attributes.,
The affixes इष्ठन् and ईयसुन् are restricted in their scope by this sutra i. e. they come only after adjectives or adverbs, in expressing comparative and superlative degrees. Thus लघीयान् , लघिष्टः, पटीयान्, पटिष्टः; but not after words like पाचक &c. There we have पाचकतरः, पाचकतमः ॥ The word एव 'only' restricts the scope of the affixes, and not of the primitives. Thus पटुतरः, पटुतमः are also valid forms.,