Declension table of ?tasthu

Neuter	Singular	Dual	Plural
Nominative	tasthu	tasthunī	tasthūni
Vocative	tasthu	tasthunī	tasthūni
Accusative	tasthu	tasthunī	tasthūni
Instrumental	tasthunā	tasthubhyām	tasthubhiḥ
Dative	tasthune	tasthubhyām	tasthubhyaḥ
Ablative	tasthunaḥ	tasthubhyām	tasthubhyaḥ
Genitive	tasthunaḥ	tasthunoḥ	tasthūnām
Locative	tasthuni	tasthunoḥ	tasthuṣu

Compound tasthu -

Adverb -tasthu