Ο ανάδοχος πρέπει να ελέγξει την ηλεκτρονική σήμανση και το μικροτσίπ.

Πρέπει is an impersonal verb. It means must, has to, or more literally it is necessary.

So Greek is structurally closer to:

• It is necessary that the contractor/adopter check...

Because of that, πρέπει does not change to agree with the subject the way many normal verbs do. You use the same πρέπει with all persons:

• πρέπει να ελέγξω = I must check
• πρέπει να ελέγξεις = you must check
• πρέπει να ελέγξει = he/she must check

The subject ο ανάδοχος belongs logically with ελέγξει, not with a personally conjugated form of πρέπει.

In Modern Greek, verbs like πρέπει are followed by να + verb form.

English often uses an infinitive, as in must check or has to check. Modern Greek normally does not use an infinitive the way English does. Instead, it uses να plus a finite verb form:

• πρέπει να ελέγξει

So να is a very normal and necessary part of this structure.

Ελέγξει is the aorist subjunctive, 3rd person singular, of ελέγχω = to check / inspect / verify.

After να, Greek chooses mainly between aspect rather than tense:

• να ελέγξει = to check, seen as one complete action
• να ελέγχει = to be checking / to check regularly, seen as ongoing or repeated

In this sentence, να ελέγξει presents the checking as a complete act the person is required to do.

This is an aspect choice.

• να ελέγξει = a single complete check
• να ελέγχει = ongoing, repeated, or habitual checking

So the sentence with ελέγξει sounds like must carry out the check. If the meaning were more like must regularly monitor/check, Greek might prefer να ελέγχει.

This is a very common Greek distinction that English speakers often need time to get used to.

Greek articles change for gender, number, and case.

In this sentence:

• ο ανάδοχος = masculine nominative singular
  
  • this is the subject
• την ηλεκτρονική σήμανση = feminine accusative singular
  
  • this is a direct object
• το μικροτσίπ = neuter accusative singular
  
  • this is also a direct object

So the different articles are showing grammatical information that English usually does not show so clearly.

Because the next word begins with a vowel: ηλεκτρονική.

In Modern Greek, the feminine accusative article can appear as τη or την, but the final -ν is normally kept before:

• vowels
• certain consonants

So before ηλεκτρονική, you normally write and say:

• την ηλεκτρονική

This is the standard form here.

Because the adjective must agree with the noun σήμανση.

Here:

• σήμανση is feminine singular
• it is the direct object, so it is in the accusative
• the adjective ηλεκτρονική matches it

So:

• την ηλεκτρονική σήμανση

This agreement is very important in Greek. Adjectives change form to match the noun they describe.

Greek very often repeats the article with each noun in a list or pair:

• την ηλεκτρονική σήμανση και το μικροτσίπ

This is natural and standard Greek. It clearly marks both nouns as separate direct objects.

English often omits the second the, but Greek commonly keeps the article with each noun, especially when the nouns are distinct items.

Yes. Ανάδοχος is one of those Greek nouns whose basic form can be used for either sex, and the article often tells you the gender:

• ο ανάδοχος = a male contractor/adopter/sponsor/fosterer, depending on context
• η ανάδοχος = a female one

So in your sentence, ο shows that it is masculine.

Also, the exact English meaning of ανάδοχος depends a lot on context. In different situations it can mean things like contractor, sponsor, godparent, foster parent, or adopter.

Μικροτσίπ is a loanword, and words like this are often treated as indeclinable or mostly indeclinable in Modern Greek.

That means the noun itself often stays the same, while the article shows the grammar:

• το μικροτσίπ
• του μικροτσίπ
• τα μικροτσίπ

So even though the article changes, the noun μικροτσίπ usually does not.

Yes, very often it is.

In official, legal, or veterinary contexts, ηλεκτρονική σήμανση is a common phrase meaning electronic identification/marking, often connected with an implanted microchip.

So although the words literally mean electronic marking, in practice the phrase can function as a technical term.

Yes. Greek word order is more flexible than English word order.

This sentence uses a very normal, neutral order:

• Ο ανάδοχος πρέπει να ελέγξει...

But other orders are possible, depending on emphasis, for example:

• Πρέπει ο ανάδοχος να ελέγξει...

That said, the original version is straightforward and natural for a learner to model.