Indefinite articles in the nominative (ein, eine, ein)

Ein and eine both mean "a" or "an" — the indefinite article, used for something new or not yet specific. This article looks at how they work in the nominative case — the form used for the subject of a sentence — building on what you saw in the article on definite articles in the nominative.

Quick shortcut: nominative singular — ein (masc.), eine (fem.), ein (neut.); nominative plural — no article at all.

Ein vs. eine: matching the noun's gender

Just like the definite article der/die/das, the indefinite article changes form to match the gender of the noun that follows it. In the nominative, masculine and neuter nouns share the same form, ein, while feminine nouns take eine:

Notice that masculine and neuter both use ein — ✅ ein Tisch (a table, masculine) and ✅ ein Buch (a book, neuter) look identical, even though the nouns have different genders. You can't tell a masculine noun from a neuter one by its indefinite article alone; that only becomes visible once you look at the definite article (der Tisch vs. das Buch) or other forms further along.

No plural form at all

Unlike the definite article, which has one shared plural form (die), there is no plural form of ein/eine/ein meaning "a/an" — it doesn't exist in the plural. For a plain indefinite plural — "children" or "some children" in a general, non-specific sense — German normally uses no article at all:

• Ein Hund ist hier. → Hunde sind hier. (A dog is here. → Dogs are here.)
• Ein Kind spielt. → Kinder spielen. (A child is playing. → Children are playing.)

This is a genuine gap, not a rule you need to memorize a form for — there's simply nothing there. If you specifically mean "some/several," German has separate words for that, like einige or ein paar; and to say "not any," German uses a different word, kein, covered in its own lesson — but for a plain plural noun with no extra meaning, no article is needed at all.

Using it as the subject

Because this article is about the nominative case, every example so far has shown ein/eine in front of the subject of the sentence. In these simple examples the subject comes first, right before the verb in second position — but more generally, the nominative marks the subject no matter where it sits in the sentence:

• Ein Hund bellt. — A dog is barking.
• Eine Katze schläft. — A cat is sleeping.
• Ein Auto kommt. — A car is coming.

The indefinite article introduces a thing the listener doesn't already know about. Once it's been mentioned, a following sentence usually switches to the definite article instead: Ein Hund bellt. Der Hund ist laut. (A dog is barking. The dog is loud.) — the second sentence uses der, not ein, because by then the listener knows exactly which dog is meant.

After "sein" (to be)

The nominative isn't only for the subject — it's also used for a noun that follows sein ("to be") to say what something is, even though that noun isn't the subject itself:

• Das ist ein Hund. — That's a dog.
• Das ist eine Katze. — That's a cat.

This is one of the most common patterns a beginner uses, and it's still the nominative ein/eine, matching the gender of the noun that follows — not the neuter das that starts the sentence, which is just a generic pointing word ("that/this").

Common mistakes

• ❌ Using eine for a masculine or neuter noun, e.g. eine Mann → ✅ ein Mann — masculine and neuter nouns both take ein in the nominative, never eine
• ❌ Adding an article to a plural noun, e.g. ❌ ein Kinder spielen → ✅ Kinder spielen — the indefinite article has no plural form, so a plain indefinite plural noun usually has no article at all
• ❌ Using the indefinite article for something already mentioned, e.g. repeating ein Hund after it was introduced → ✅ der Hund — once the listener knows which one you mean, you usually switch to the definite article
• ❌ Assuming ein only means "a," never "one" → ein/eine/ein can also mean the number "one," especially when stressed (Ich habe nur ein Buch = "I have only one book")

Quick check

Fill in the correct indefinite article (ein or eine), or leave the blank empty if none is needed:

1. ___ Buch liegt hier. (book, neuter)
2. ___ Frau steht dort. (woman, feminine)
3. ___ Kinder spielen. (children, plural)
4. ___ Mann liest. (man, masculine)

Key takeaways

• Ein is the nominative indefinite article for masculine and neuter nouns; eine is used for feminine nouns.
• The indefinite article has no plural form — a plural noun simply appears without any article at all.
• The indefinite article introduces something new or not yet specific; once it's been mentioned, later sentences typically switch to the definite article (der/die/das) instead.
• The nominative also appears after sein ("to be"), as in Das ist ein Hund — not just for the sentence's subject.
• Masculine and neuter nouns look identical in the indefinite article (ein), unlike in the definite article, where they're distinguished (der vs. das).