Der Diebstahl ist eine Straftat.

In German, it is very common to use the definite article with nouns, even when speaking about something in a general sense.

So Der Diebstahl ist eine Straftat is a normal way to say Theft is a crime.

English often drops the article in general statements:

• Theft is illegal
• Honesty is important

German often keeps it:

• Der Diebstahl ist ...
• Die Ehrlichkeit ist ...

You may sometimes see article-less versions in certain styles, but for a learner, Der Diebstahl is the standard and safest form here.

Diebstahl is a masculine noun, so its nominative singular article is der.

In German, grammatical gender must usually be learned with the noun:

• der Diebstahl
• die Straftat
• das Haus

There is not always a reliable rule that tells you the gender just from the meaning. So it is best to memorize nouns together with their article.

German very often forms nouns by combining smaller words into a single compound noun.

Here:

• Straf- relates to punishment or penal
• Tat means deed or act

So Straftat literally means something like criminal act or offense, and in natural English here it is often translated as crime.

This one-word spelling is completely normal in German.

Straftat is a feminine noun, so its singular indefinite article is eine.

That is why we say:

• eine Straftat

Compare:

• masculine: ein Diebstahl
• feminine: eine Straftat
• neuter: ein Verbrechen

Again, gender is something you usually need to learn with the noun:

• die Straftat

German main clauses normally follow the verb-second rule. That means the conjugated verb comes in the second position.

In this sentence:

• Der Diebstahl = first element
• ist = second element
• eine Straftat = the rest

So the structure is:

• Subject + verb + complement

This is very typical German word order in a simple statement.

Both noun phrases are in the nominative.

• Der Diebstahl is the subject, so it is nominative.
• After the verb sein (to be), the noun that identifies or describes the subject is also nominative.

So:

• der Diebstahl
• eine Straftat

This is different from some other verbs, where the second noun might be accusative.

Good question. In feminine singular, the indefinite article is:

• nominative: eine
• accusative: eine

So the form is the same in both cases.

That means in this sentence, eine Straftat is nominative because of the grammar after sein, even though it looks identical to the accusative form.

Because all nouns in German are capitalized.

So:

• der Diebstahl
• eine Straftat

This is one of the most noticeable spelling differences from English. In German, capitalization is a very useful clue that a word is a noun.

Yes. Diebstahl is the noun meaning theft, and it is related to the verb stehlen, which means to steal.

Related forms:

• stehlen = to steal
• der Diebstahl = theft
• der Dieb = thief

The spelling changes are not fully transparent for beginners, so it is best to learn them as a word family rather than trying to guess them.

Yes, that is possible, but it is not exactly the same in nuance.

• eine Straftat = a criminal offense / a punishable act
• ein Verbrechen = a crime, and in legal contexts sometimes specifically a more serious crime

In everyday English, both may be translated as crime, but Straftat is the broader and safer word in this sentence.

A rough English-friendly guide is:

• Der ≈ dare with a lighter r
• Diebstahl ≈ DEEP-shtahl
• ist ≈ ist
• eine ≈ EYE-nuh
• Straftat ≈ SHTRAHF-taht

A few helpful notes:

• ie in German usually sounds like English ee
• st at the beginning of a syllable is often pronounced sht
• ahl has a long a sound

So Diebstahl is approximately DEEP-shtahl.