Declension table of ?sumātṛ

Masculine	Singular	Dual	Plural
Nominative	sumātā	sumātārau	sumātāraḥ
Vocative	sumātaḥ	sumātārau	sumātāraḥ
Accusative	sumātāram	sumātārau	sumātṝn
Instrumental	sumātrā	sumātṛbhyām	sumātṛbhiḥ
Dative	sumātre	sumātṛbhyām	sumātṛbhyaḥ
Ablative	sumātuḥ	sumātṛbhyām	sumātṛbhyaḥ
Genitive	sumātuḥ	sumātroḥ	sumātṝṇām
Locative	sumātari	sumātroḥ	sumātṛṣu

Compound sumātṛ -

Adverb -sumātṛ