Στον ποδηλατόδρομο ελέγχω τον ανακλαστήρα πάνω στη σχάρα.

Στον is the usual contraction of σε + τον.

So:

• σε = in, on, at, to
• τον = the, masculine accusative singular
• στον = σε τον

This contraction is completely normal in everyday Greek.

So στον ποδηλατόδρομο literally means on/in the bike lane.

In Modern Greek, the preposition σε normally takes the accusative.

That is true whether you mean:

• movement toward somewhere
• location in/at/on somewhere

So after σε, you usually expect the accusative:

• στον ποδηλατόδρομο
• στο σπίτι
• στην πόλη

Even though English might use a location idea like on the bike path, Greek still uses the accusative here.

Because the verb already shows the subject.

ελέγχω means I check / I am checking. The ending -ω tells you it is first person singular.

Greek often leaves out subject pronouns when they are clear from the verb form. So:

• ελέγχω = I check
• εγώ ελέγχω = I check with extra emphasis on I

So the sentence does not need εγώ unless the speaker wants contrast or emphasis.

Because ανακλαστήρα is the direct object of the verb ελέγχω.

The basic pattern is:

• ο ανακλαστήρας = the reflector, nominative, used as the subject
• τον ανακλαστήρα = the reflector, accusative, used as the object

Since the sentence says I check the reflector, the reflector is what is being checked, so it must be in the accusative:

• ελέγχω τον ανακλαστήρα

It means on the rack or more literally on top of the rack.

Breakdown:

• πάνω = up, above, on top
• στη = σε + τη(ν), meaning in/on/at the
• σχάρα = rack, grille, grate, depending on context

So πάνω στη σχάρα is a natural way to say that something is physically positioned on the rack.

Both forms come from σε + την.

• στην is the full form
• στη is the shortened form, with the final -ν dropped

In Modern Greek, the final -ν is often dropped before many consonants. Since σχάρα starts with σχ-, στη σχάρα is completely normal.

So:

• στη σχάρα = natural and common
• στην σχάρα = possible as a fuller spelling/pronunciation in some contexts

Most naturally, it describes the reflector:

• I check the reflector [that is] on the rack

That is because πάνω στη σχάρα comes right after τον ανακλαστήρα, so it most easily attaches to that noun phrase.

Also, the sentence already has another location phrase:

• Στον ποδηλατόδρομο = on the bike path

So the most likely reading is:

• On the bike path, I check the reflector that is on the rack.

In real conversation, context would confirm this.

Because Greek uses definite articles very regularly, often more often than English.

Here you have:

• στον ποδηλατόδρομο = on the bike path
• τον ανακλαστήρα = the reflector
• στη σχάρα = on the rack

In Greek, articles are a normal part of noun phrases, especially when talking about specific things. English sometimes drops the where Greek keeps it, but in this sentence the articles are fully expected.

Yes.

ελέγχω is the present tense, and like many present forms in Greek, it can correspond to either:

• I check
• I am checking

The exact English translation depends on context.

So this sentence could be understood as either a general present or an action happening now, depending on the situation.

It is a compound noun meaning bike lane or cycle path.

It is made from elements related to:

• ποδήλατο = bicycle
• δρόμος = road, street, way

Its dictionary form is:

• ο ποδηλατόδρομος

In the sentence, after στον, it appears in the accusative singular:

• τον ποδηλατόδρομο
• contracted with σε: στον ποδηλατόδρομο

Yes, Greek word order is fairly flexible, though some orders sound more natural than others.

This sentence:

• Στον ποδηλατόδρομο ελέγχω τον ανακλαστήρα πάνω στη σχάρα.

could also be rearranged in some contexts, for example to emphasize a different part. But the given order is natural and easy to understand:

1. setting/place: Στον ποδηλατόδρομο
2. verb: ελέγχω
3. object: τον ανακλαστήρα
4. extra location/detail: πάνω στη σχάρα

So the current version sounds like a normal descriptive sentence.