Declension table of ?prathamasvara

Neuter	Singular	Dual	Plural
Nominative	prathamasvaram	prathamasvare	prathamasvarāṇi
Vocative	prathamasvara	prathamasvare	prathamasvarāṇi
Accusative	prathamasvaram	prathamasvare	prathamasvarāṇi
Instrumental	prathamasvareṇa	prathamasvarābhyām	prathamasvaraiḥ
Dative	prathamasvarāya	prathamasvarābhyām	prathamasvarebhyaḥ
Ablative	prathamasvarāt	prathamasvarābhyām	prathamasvarebhyaḥ
Genitive	prathamasvarasya	prathamasvarayoḥ	prathamasvarāṇām
Locative	prathamasvare	prathamasvarayoḥ	prathamasvareṣu

Compound prathamasvara -

Adverb -prathamasvaram -prathamasvarāt