Is Kombi der, die or das?

The correct German article for Kombi is der. The noun Kombi is Masculine. So you always say: der Kombi. Learn the article together with the noun — German nouns don't follow predictable gender rules most of the time.

The plural of Kombi is: die Kombis. In the plural, every German noun takes the article "die". So: die Kombis. Example: ein Kombi → zwei Kombis.

Correct: die Kombis. The form "die Kombis" is wrong. The plural of der Kombi is die Kombis. In the nominative plural, you always use the article "die".

der Kombi follows the four German cases. Nominative: der Kombi, Accusative: den Kombi, Dative: dem Kombi, Genitive: des Kombis. In plural: die Kombis / den Kombis. Learn these forms together with the noun.

The genitive singular of der Kombi is: des Kombis. The genitive plural is der Kombis. German uses the genitive to express possession or belonging. Example: die Farbe des Kombis.

The dative plural of Kombi is: den Kombis. In German, dative plural nouns usually end in "-n". So you say: "mit den Kombis". Use this case after prepositions like mit, von, bei, zu.

Kombi is a noun and must be capitalized in German. You'll find example sentences above for each case. The article der stays the same in nominative singular but changes in other cases. Practice declension in your own sentences.

Yes, Kombi is a noun (also called a substantive). German nouns are always capitalized. The article for Kombi is der. Every German noun has a fixed article you must memorize.