Declension table of ?yasyatva

Neuter	Singular	Dual	Plural
Nominative	yasyatvam	yasyatve	yasyatvāni
Vocative	yasyatva	yasyatve	yasyatvāni
Accusative	yasyatvam	yasyatve	yasyatvāni
Instrumental	yasyatvena	yasyatvābhyām	yasyatvaiḥ
Dative	yasyatvāya	yasyatvābhyām	yasyatvebhyaḥ
Ablative	yasyatvāt	yasyatvābhyām	yasyatvebhyaḥ
Genitive	yasyatvasya	yasyatvayoḥ	yasyatvānām
Locative	yasyatve	yasyatvayoḥ	yasyatveṣu

Compound yasyatva -

Adverb -yasyatvam -yasyatvāt