Auf dem alten Tisch ist schon ein kleiner Kratzer, aber meine Schwester stört das nicht.

German often puts a location or time expression first for emphasis or simply for style. When that happens, the verb still has to stay in second position in the clause.

So:

• Auf dem alten Tisch = first element
• ist = second position
• schon ein kleiner Kratzer = the rest of the clause

This follows the normal German verb-second rule for main clauses.

A more neutral version would be:

• Schon ist ein kleiner Kratzer auf dem alten Tisch.
• Ein kleiner Kratzer ist schon auf dem alten Tisch.

All of these are possible, but the original puts focus on the table first.

Because this phrase describes a location, not a movement.

German prepositions like auf can take either:

• dative for location: on the table
• accusative for movement toward a destination: onto the table

Here, the scratch already exists on the table, so the location is static:

• auf dem alten Tisch = on the old table
  (dem = dative)

If it were movement, you would use accusative:

• Ich lege das Buch auf den alten Tisch. = I put the book onto the old table.

It is dative masculine singular.

The noun Tisch is masculine: der Tisch.
After auf in a location meaning, it takes dative, so:

• der Tisch → dem Tisch

The adjective ending also changes:

• dem alten Tisch

So the whole phrase is:

• auf dem alten Tisch = on the old table

Here schon means something like already.

So ist schon ein kleiner Kratzer suggests that the scratch is already there, perhaps earlier than expected or unfortunately present now.

Depending on context, schon can also have other meanings in German, such as:

• reassurance: Das wird schon.
• emphasis: Das ist schon richtig.
• yes, but...: Schon, aber...

In this sentence, though, the natural meaning is already.

It is nominative singular, because ein kleiner Kratzer is the grammatical subject of the first clause.

The core structure is:

• Ein kleiner Kratzer ist auf dem alten Tisch.

Even though the sentence begins with Auf dem alten Tisch, the subject is still ein kleiner Kratzer.

Because Kratzer is masculine and singular, with ein in the nominative, you get:

• ein kleiner Kratzer

Yes. In German, the subject does not always come first.

In the clause:

• Auf dem alten Tisch ist schon ein kleiner Kratzer

the subject is ein kleiner Kratzer, even though it appears after the verb.

German word order is more flexible than English. The key rule in a main clause is that the finite verb is in second position, not that the subject must come first.

Both are possible, but they mean slightly different things in terms of focus.

• Meine Schwester stört das nicht puts more focus on my sister
• Das stört meine Schwester nicht puts more focus on that

In the original, meine Schwester comes first because it is the topic of the second clause: we are now talking about her reaction.

Also notice that stören works differently from English to bother in terms of structure:

• Das stört meine Schwester nicht. = That does not bother my sister.
• literally: That disturbs my sister not

So das is the thing causing annoyance, and meine Schwester is the person affected.

Stören usually takes:

• the thing that bothers someone as the subject (nominative)
• the person bothered as the object (accusative)

So in a basic sentence:

• Das stört meine Schwester.
• literally: That bothers my sister.

Breakdown:

• das = subject, nominative
• meine Schwester = accusative object

In the original sentence:

• aber meine Schwester stört das nicht

the word order is changed, but the roles stay the same:

• das is still the subject
• meine Schwester is still the accusative object

A useful comparison:

• Ich störe meine Schwester. = I bother my sister.
• Meine Schwester stört mich. = My sister bothers me.

Das refers back to the previous idea: namely, the fact that there is already a small scratch on the table.

So here das means something like:

• that
• that fact
• it, in a broad sense

German often uses das to refer to a whole situation or previous statement.

So:

• aber meine Schwester stört das nicht = but that doesn’t bother my sister

Here nicht negates the verb phrase stört das in the sense of does not bother.

So:

• meine Schwester stört das nicht means
• that does not bother my sister

In other words, the negation applies to the whole idea that this situation bothers her.

If you changed the position of nicht, the meaning or emphasis could change. In this sentence, the placement is natural and standard.

Because the subject is singular:

• ein kleiner Kratzer = a small scratch

Since Kratzer is singular, the verb must also be singular:

• ist

If the subject were plural, you would say:

• Auf dem alten Tisch sind schon kleine Kratzer. = There are already small scratches on the old table.

Yes, very much.

German often expresses existence simply with sein plus a noun phrase and a location:

• Auf dem alten Tisch ist schon ein kleiner Kratzer.

A natural English translation is:

• There is already a small scratch on the old table.

German does not need a dummy subject like English there in this kind of sentence.

Because aber introduces a new main clause, and in standard German spelling, clauses joined with coordinating conjunctions like aber are separated with a comma.

So:

• ..., aber meine Schwester stört das nicht.

This is normal German punctuation.

In English, punctuation rules are a bit different and more style-dependent, but in German this comma is standard.

Yes, it can.

Although schon literally means already, in context it can suggest something like:

• there’s already a small scratch
• there’s even already a small scratch
• unfortunately, there’s already a scratch

So it can carry a slight emotional coloring depending on tone and context. The speaker may be implying that the scratch is regrettable, surprising, or worth noticing.

They show case, gender, and article pattern.

1. dem alten Tisch

• dem = dative masculine singular
• after a definite article like dem, the adjective takes a weak ending
• so: alten

2. ein kleiner Kratzer

• ein = nominative masculine singular
• with ein-words, the adjective often has to carry more grammatical information
• so you get: kleiner

That is why the forms are:

• dem alten Tisch
• ein kleiner Kratzer

Yes, that is also correct.

• Auf dem alten Tisch ist schon ein kleiner Kratzer
• Auf dem alten Tisch gibt es schon einen kleinen Kratzer

Both can mean There is already a small scratch on the old table.

A small grammar difference:

• with ist, ein kleiner Kratzer is nominative
• with gibt es, einen kleinen Kratzer is accusative

So:

• ist schon ein kleiner Kratzer
• gibt es schon einen kleinen Kratzer

Both are natural, though ist may sound a little simpler and more direct here.

Usually das is better here.

Why? Because das refers back to the whole previous situation: the scratch being there.

• Das stört meine Schwester nicht. = That doesn’t bother my sister.

Using es would be less natural if you want to point back clearly to the whole idea. Es usually works more like it, while das often points to a previously mentioned statement, event, or situation.

So in this sentence, das is the more idiomatic choice.

The underlying structure is:

• Das stört meine Schwester nicht.

This is:

• Das = subject
• stört = verb
• meine Schwester = object
• nicht = negation

In the actual sentence, meine Schwester is moved to the front for emphasis or topic:

• Meine Schwester stört das nicht.

Because it is still a main clause, the verb remains in second position:

• first element: meine Schwester
• second position: stört

So the sentence is correct even though the subject is not first.

There are two clues.

1. The verb stören

As a normal pattern, stören takes the affected person in the accusative:

• Das stört mich.
• Das stört ihn.
• Das stört meine Schwester.

2. Meaning and structure

What is doing the bothering? das.
Who is being bothered? meine Schwester.

With a feminine noun like Schwester, nominative and accusative look the same:

• meine Schwester can be nominative or accusative in form

So here you identify the case mostly through the verb pattern and meaning, not through the article form alone.

Not very naturally.

A very literal version would be something like:

• On the old table is already a small scratch, but my sister bothers that not.

That is understandable, but not natural English.

A natural English rendering would be:

• There is already a small scratch on the old table, but that doesn’t bother my sister.

This is a good example of how German and English often use different word order even when the meaning is the same.