An dieser Stelle ist der Weg glatt.

Because an is a two-way preposition in German, and here it describes a location rather than movement.

• movement toward a place → accusative
• location in/at a place → dative

In An dieser Stelle, the meaning is at this spot / at this point, so German uses the dative.

• die Stelle = nominative
• an dieser Stelle = dative

Also, Stelle is a feminine noun, so the form of dieser must match:

• nominative feminine: diese
• dative feminine: dieser

So an dieser Stelle is the correct form.

It is an adverbial phrase of place. It tells you where the path is slippery/smooth.

So the sentence structure is basically:

• An dieser Stelle = at this spot / here
• ist = is
• der Weg = the path
• glatt = slippery/smooth

It answers the question Where is the path glatt?

This is because German follows the verb-second rule in main clauses.

The finite verb must come in position 2, but the first position can be taken by many different elements, not just the subject.

Here, the speaker puts the location first:

1. An dieser Stelle
2. ist
3. der Weg
4. glatt

If you started with the subject instead, you could also say:

• Der Weg ist an dieser Stelle glatt.

That is also correct. The original version puts more emphasis on the location.

Der Weg is in the nominative case because it is the subject of the sentence.

You can test this by asking: What is glatt?
Answer: der Weg

So:

• der Weg = subject, nominative
• ist = verb
• glatt = predicate adjective

Because der Weg is the subject of the sentence, and subjects are in the nominative case.

Here is the noun by case:

• nominative: der Weg
• accusative: den Weg
• dative: dem Weg
• genitive: des Weges

In this sentence, the path is not an object; it is the thing being described, so German uses der Weg.

Because glatt is not being used before a noun. It is being used after the verb sein, as a predicate adjective.

Compare:

• der glatte Weg = the smooth/slippery path
  → adjective before the noun, so it takes an ending

• der Weg ist glatt = the path is smooth/slippery
  → adjective after sein, so no ending

This is very common in German:

• Das Wasser ist kalt.
• Die Straße ist nass.
• Der Boden ist rutschig.

Literally, glatt often means smooth. But in sentences about roads, paths, or ground, it often means slippery, especially because of ice, water, or a slick surface.

So in this sentence, the natural meaning is usually:

• The path is slippery at this spot.

German often uses glatt in weather or road conditions:

• Die Straße ist glatt. = The road is slippery.

So even though the basic meaning is smooth, the practical meaning here is likely slippery.

Yes. That is completely correct.

Both versions are natural:

• An dieser Stelle ist der Weg glatt.
• Der Weg ist an dieser Stelle glatt.

The difference is mainly focus:

• An dieser Stelle ... emphasizes the location
• Der Weg ... emphasizes the path

German is flexible about what comes first, but the verb still stays in second position.

German usually uses an article where English sometimes does not.

In English, you might say:

• Road ahead slippery
• Path slippery here

But in normal German, you usually need the article:

• der Weg

Leaving it out would sound unnatural in a standard sentence like this.

So:

• natural: Der Weg ist glatt.
• unnatural here: Weg ist glatt.

Both can refer to a place, but they are not always used in exactly the same way.

• Stelle often means a specific spot/point
• Ort is more like place/location in a broader sense

In this sentence, an dieser Stelle sounds very natural because it suggests this particular patch of the path.

So:

• An dieser Stelle = at this exact spot
• An diesem Ort = at this place

The sentence with Stelle sounds more precise.

Yes. German prepositions do not match English ones exactly.

An can mean different things depending on context, for example:

• at
• on
• by
• sometimes to

In an dieser Stelle, the best English translation is usually at this spot or at this point.

So you should not try to match an to only one English preposition. Its meaning depends on the phrase and the situation.

Here, dieser is functioning like a demonstrative determiner modifying the noun Stelle.

It is similar to this in English:

• this spot

In German grammar, it is often described as a demonstrative article or demonstrative determiner when it comes before a noun.

So in:

• an dieser Stelle

dieser is describing Stelle and agrees with it in:

• gender: feminine
• number: singular
• case: dative

Then an would usually take the accusative instead of the dative.

Compare:

• An dieser Stelle ist der Weg glatt.
  = location → dative

• Ich gehe an diese Stelle.
  = movement toward that spot → accusative

So the contrast is:

• dieser Stelle = at this spot
• diese Stelle = to this spot

That is one of the most important patterns with German two-way prepositions.