German Phrase
Das ist ein schwarzer Koffer mit einem roten Gurt.
Meaning
This sentence identifies an object: a black suitcase that has a red strap. It combines a simple identification (Das ist…) with a descriptive phrase that uses the dative case after the preposition "mit".
When to use
Use this structure when you need to point out or describe a specific item, especially in travel, luggage‑checking, or shopping contexts. It works well in both spoken and written German when you want to give a quick visual description.
✦Grammar Breakdown
DasisteinschwarzerKoffermiteinemrotenGurt.
Verb "sein" (ist)
The verb "sein" is used as a copula and does not take an object; it simply links the subject to a predicate noun or adjective.
Indefinite article "ein" (Nominativ, maskulin)
In the nominative masculine singular, "ein" has no ending; it signals an indefinite noun.
Adjective ending "-er" (schwarzer)
After an indefinite article in the nominative masculine, the adjective takes the weak ending "-er".
Preposition "mit" + Dative
"Mit" always governs the dative case, so the noun phrase after it must be in dative.
Dative article "einem" (maskulin)
The masculine dative indefinite article is "einem".
Adjective ending "-en" (roten)
In the dative masculine after an indefinite article, the adjective takes the ending "-en".
🗨In Conversation
Was ist das?
What is that?
Das ist ein schwarzer Koffer mit einem roten Gurt.
That is a black suitcase with a red strap.
✕Common Mistakes
Das ist ein schwarzes Koffer mit einem roten Gurt.
After the indefinite article "ein" in the nominative masculine, the adjective takes the weak ending "-er", not "-es".
Das ist ein schwarzer Koffer mit ein roter Gurt.
The preposition "mit" requires the dative case, so the article must be "einem" and the adjective "roten".
Das ist ein schwarzer Koffer mit einem rot Gurt.
Adjectives in the dative masculine after an indefinite article need the ending "-en".
↔Alternatives
Das ist ein schwarzer Koffer, der einen roten Gurt hat.
That is a black suitcase that has a red strap.
Hier ist ein schwarzer Koffer mit rotem Gurt.
Here is a black suitcase with a red strap.
Ein schwarzer Koffer mit rotem Gurt steht hier.
A black suitcase with a red strap is standing here.
Cultural Tip
German nouns are always capitalized, and adjective endings change with case, gender, and article type. In everyday speech, Germans often drop the article after "mit" in informal contexts (e.g., "mit rotem Gurt"), but the full dative form shown here is the grammatically correct version for learners.