Declension table of ?tatatva

Neuter	Singular	Dual	Plural
Nominative	tatatvam	tatatve	tatatvāni
Vocative	tatatva	tatatve	tatatvāni
Accusative	tatatvam	tatatve	tatatvāni
Instrumental	tatatvena	tatatvābhyām	tatatvaiḥ
Dative	tatatvāya	tatatvābhyām	tatatvebhyaḥ
Ablative	tatatvāt	tatatvābhyām	tatatvebhyaḥ
Genitive	tatatvasya	tatatvayoḥ	tatatvānām
Locative	tatatve	tatatvayoḥ	tatatveṣu

Compound tatatva -

Adverb -tatatvam -tatatvāt