Declension table of siddhatva

Neuter	Singular	Dual	Plural
Nominative	siddhatvam	siddhatve	siddhatvāni
Vocative	siddhatva	siddhatve	siddhatvāni
Accusative	siddhatvam	siddhatve	siddhatvāni
Instrumental	siddhatvena	siddhatvābhyām	siddhatvaiḥ
Dative	siddhatvāya	siddhatvābhyām	siddhatvebhyaḥ
Ablative	siddhatvāt	siddhatvābhyām	siddhatvebhyaḥ
Genitive	siddhatvasya	siddhatvayoḥ	siddhatvānām
Locative	siddhatve	siddhatvayoḥ	siddhatveṣu

Compound siddhatva -

Adverb -siddhatvam -siddhatvāt