There cannot be 2 Nominatives in the same sentence. Don’t forget to use the direct object (accusative) when needed.

The solid way to express cases in German is to use the definite/indefinite article or the possessive pronoun. The accusative form defers from the nominative only in the case of nouns which are masculine (der-den, but die-die, das-das). Thus, the above imperative (don’t forget to use the direct object) refers in the first place to the nouns which are masculine.

Here are the most common scenarios at the A1 level.

• Use the direct object (accusative) after these most frequent verbs:

haben
suchen
brauchen
es gibt
sehen
kaufen
möchten
trinken
essen
schreiben
lesen
bestellen
tragen
verstehen
finden + Adjective (for example: ich finde den Film gut)
stellen
legen
hängen
anrufen
anmachen
ausmachen
einschalten
ausschalten
aufmachen
zumachen
halten
mitbringen
holen
nehmen
besuchen*                                                                                                                          *tip: all verbs (except begegnen) which start with be- demand direct object (accusative).

• after these prepositions: für, um, durch, ohne, gegen (example: er geht um das Haus)
• after in, an, auf, hinter, vor, neben, zwischen, über, unter only when it answers to the question “wohin?” ( example: er stellt den Teller auf den Tisch.