أَنَا طَالِبٌ.
Anā: independent indeclinable pronoun, subject of the nominal clause in the nominative position; ṭālibun: nominative predicate.
نَحْنُ مُجْتَهِدُونَ.
Naḥnu: independent pronoun in the nominative position; mujtahidūna: nominative predicate with wāw (sound masculine plural).
The pronoun’s indeclinability does not remove case from the predicate.