Das Hähnchen ist im Ofen.

Because Hähnchen is a neuter noun in German, so it takes das in the singular: das Hähnchen.

A useful clue is the ending -chen. In German, nouns ending in -chen are always neuter. So:

• das Hähnchen = the chicken
• das Mädchen = the girl
• das Brötchen = the bread roll

The ending -chen is a diminutive ending. It often gives the idea of something small, cute, or little.

So Hahn means rooster/cock, and Hähnchen originally means something like little chicken. In modern everyday German, Hähnchen often refers to chicken meat, especially a cooked or roast chicken.

Also, when a noun takes -chen, it becomes neuter, which is why we say das Hähnchen.

This is a common pattern in German word formation. When some nouns take a diminutive ending like -chen, the vowel often changes to an umlaut if possible.

So:

• Hahn → Hähnchen

This kind of vowel change is very common in German and just has to be learned as part of the word.

Ist is the third-person singular form of the verb sein (to be).

The full present-tense forms of sein are:

• ich bin
• du bist
• er/sie/es ist
• wir sind
• ihr seid
• sie/Sie sind

Since das Hähnchen is a singular subject, German uses ist.

Im is a contraction of in dem:

• im = in dem

And Ofen is a masculine noun:

• der Ofen = the oven

So in dem Ofen becomes im Ofen.

It is not in der Ofen because der is nominative masculine, but after in we need a different case here.

It is not in den Ofen here because that would usually mean into the oven rather than in the oven.

The preposition in can take either:

• dative for location: where something is
• accusative for direction/movement toward somewhere

In Das Hähnchen ist im Ofen, the sentence describes location: the chicken is in the oven. There is no movement into it being expressed. So German uses the dative:

• in dem Ofen → im Ofen

Compare:

• Das Hähnchen ist im Ofen. = The chicken is in the oven.
• Ich lege das Hähnchen in den Ofen. = I put the chicken into the oven.

Here it is singular because it has the article das and the verb ist.

A tricky point: the plural form die Hähnchen looks the same as the singular noun form Hähnchen. The article tells you the difference:

• das Hähnchen ist = the chicken is
• die Hähnchen sind = the chickens are

So in your sentence, it is clearly singular.

In German, all nouns are capitalized, not just proper names.

So:

• das Hähnchen
• der Ofen

This is one of the most noticeable differences from English spelling.

A rough English-friendly guide is:

• Hähnchen ≈ HEHN-khyen or HEHN-chen, depending on how precise you want to be

A few important points:

• ä is somewhat like the vowel in air or bed, depending on accent
• hn is pronounced smoothly; the h is not strongly sounded by itself here
• ch in -chen is the soft German ich-Laut, not the English ch in church

So -chen is not pronounced like chen in English. It is a soft, breathy sound.

Not exactly.

• das Huhn usually means chicken as the animal, or hen in some contexts
• das Hähnchen often refers to a young chicken, or very commonly chicken meat / roast chicken

So in a sentence like Das Hähnchen ist im Ofen, Hähnchen sounds very natural because it suggests the chicken as food being cooked.

Yes, grammatically that is correct. In dem Ofen and im Ofen mean the same thing.

But in normal everyday German, im Ofen is much more natural because German very often contracts:

• in dem → im
• an dem → am
• zu dem → zum
• bei dem → beim

So Das Hähnchen ist im Ofen is the most natural version.

This is the standard German main-clause word order:

1. Subject: Das Hähnchen
2. Verb: ist
3. The rest of the sentence: im Ofen

German main clauses usually put the finite verb in second position. Here, the subject comes first, so the verb comes right after it.

You could change the emphasis by moving im Ofen to the front:

• Im Ofen ist das Hähnchen.

That is possible, but the basic neutral order is:

• Das Hähnchen ist im Ofen.