Declension table of ?kaṣṭārthatva

Neuter	Singular	Dual	Plural
Nominative	kaṣṭārthatvam	kaṣṭārthatve	kaṣṭārthatvāni
Vocative	kaṣṭārthatva	kaṣṭārthatve	kaṣṭārthatvāni
Accusative	kaṣṭārthatvam	kaṣṭārthatve	kaṣṭārthatvāni
Instrumental	kaṣṭārthatvena	kaṣṭārthatvābhyām	kaṣṭārthatvaiḥ
Dative	kaṣṭārthatvāya	kaṣṭārthatvābhyām	kaṣṭārthatvebhyaḥ
Ablative	kaṣṭārthatvāt	kaṣṭārthatvābhyām	kaṣṭārthatvebhyaḥ
Genitive	kaṣṭārthatvasya	kaṣṭārthatvayoḥ	kaṣṭārthatvānām
Locative	kaṣṭārthatve	kaṣṭārthatvayoḥ	kaṣṭārthatveṣu

Compound kaṣṭārthatva -

Adverb -kaṣṭārthatvam -kaṣṭārthatvāt