Declension table of ?cartavya

Masculine	Singular	Dual	Plural
Nominative	cartavyaḥ	cartavyau	cartavyāḥ
Vocative	cartavya	cartavyau	cartavyāḥ
Accusative	cartavyam	cartavyau	cartavyān
Instrumental	cartavyena	cartavyābhyām	cartavyaiḥ cartavyebhiḥ
Dative	cartavyāya	cartavyābhyām	cartavyebhyaḥ
Ablative	cartavyāt	cartavyābhyām	cartavyebhyaḥ
Genitive	cartavyasya	cartavyayoḥ	cartavyānām
Locative	cartavye	cartavyayoḥ	cartavyeṣu

Compound cartavya -

Adverb -cartavyam -cartavyāt