Declension table of ?hārdvan

Neuter	Singular	Dual	Plural
Nominative	hārdva	hārdvnī hārdvanī	hārdvāni
Vocative	hārdvan hārdva	hārdvnī hārdvanī	hārdvāni
Accusative	hārdva	hārdvnī hārdvanī	hārdvāni
Instrumental	hārdvanā	hārdvabhyām	hārdvabhiḥ
Dative	hārdvane	hārdvabhyām	hārdvabhyaḥ
Ablative	hārdvanaḥ	hārdvabhyām	hārdvabhyaḥ
Genitive	hārdvanaḥ	hārdvanoḥ	hārdvanām
Locative	hārdvani	hārdvanoḥ	hārdvasu

Compound hārdva -

Adverb -hārdva -hārdvam