Learn Hardcore German: Zehn Vögel sitzen auf dem Baum.

In German, cardinal numbers (eins, zwei, zehn …) act like determiners themselves. You normally don’t add an extra article after a number. So you say zwei Hunde, drei Bücher, zehn Vögel, not die zehn Vögel (unless you want to specify “the ten birds” out of a larger group).

How is the plural form Vögel formed from Vogel?

Vogel is a strong masculine noun that forms its plural by adding an umlaut to the stem vowel and no additional ending. Thus der Vogel → die Vögel. Other examples: der Mann → die Männer, der Apfel → die Äpfel.

What case is Zehn Vögel in, and how can I tell?

Zehn Vögel is in the nominative case because it is the subject of the sentence (the ones doing the sitting). In German, the subject takes nominative, and here there’s no article or adjective ending to change—just the plain plural noun.

Why is auf dem Baum in the dative case?

The preposition auf is a Wechselpräposition (two-way preposition).

With motion (Wohin?), it takes accusative: Er klettert auf den Baum.
With location (Wo?), it takes dative. Here we ask “Where are the birds?” → location → dative: dem is the dative of der (masculine), so auf dem Baum.

Why is the verb sitzen in second position instead of at the end?

In main clauses, German uses Verb-Second (V2) word order: the finite (conjugated) verb must occupy the second slot. Whatever you front (Zehn Vögel, Heute, Auf dem Baum…) the verb stays in position two, and the rest follows.

Why don’t we have a word like English “there” at the start (“There are ten birds…”)?

German typically doesn’t use an expletive “there” like English. You either start with the subject or a prepositional phrase. If you want an existential construction, you use es gibt: Es gibt zehn Vögel auf dem Baum. Otherwise, you simply say Zehn Vögel sitzen auf dem Baum. Starting with Es sitzen zehn Vögel… is grammatically possible but less common.

How would you ask “How many birds are sitting on the tree?” in German?

Use Wie viele for “how many”:
Wie viele Vögel sitzen auf dem Baum?

Can you turn the sentence into a yes/no question by inverting subject and verb?

Yes. For a yes/no question, put the verb first:
Sitzen zehn Vögel auf dem Baum?

How can you emphasize that it’s exactly ten birds?

Add an adverb like genau, gerade or ausgerechnet:

Gerade zehn Vögel sitzen auf dem Baum.
Es sind genau zehn Vögel auf dem Baum.
Auf dem Baum sitzen ausgerechnet zehn Vögel!

How do you pronounce the umlaut ö in Vögel?

The German ö sounds like a mid-front rounded vowel. Imagine saying the English word “bird” without the “r” sound, with slightly rounded lips. Alternatively, it’s close to the French eu in peur.