Kampçı ünitesinin gecelik ücreti girişte ödendi.

Because it contains two layers of grammar:

• ünite = unit
• ünitesi = camper unit as part of the noun compound kampçı ünitesi
• ünitesinin = of the camper unit

More specifically:

• In kampçı ünitesi, the second noun takes the 3rd person possessive ending -si. This is how many Turkish noun compounds work.
• Then the whole phrase is put into the genitive (-nin) to mean of the camper unit.

So:

• kampçı ünitesi = camper unit
• kampçı ünitesinin = of the camper unit

The extra n before -in is a normal buffer consonant.

Not exactly. Kampçı is basically a noun meaning something like camper or camp user, but here it functions as the first part of a noun compound.

So kampçı ünitesi is structurally more like:

• student card
• coffee cup
• hotel room

in English, where the first word is a noun used to describe the second.

Because Turkish usually marks both sides of a possession phrase.

Here, kampçı ünitesinin is the possessor (of the camper unit), so the thing possessed, ücret, takes the 3rd person possessive ending:

• ücret = fee
• ücreti = its fee / the fee of it

So the pattern is:

• [possessor + genitive] + [possessed noun + possessive ending]

In this sentence:

• kampçı ünitesinin gecelik ücreti = the camper unit’s nightly fee

Gecelik comes from:

• gece = night
• -lik = a suffix that can create meanings like for, related to, or per

Here gecelik means nightly or per night.

So:

• gecelik ücret = nightly fee / fee per night

In the sentence, gecelik works like an adjective describing ücreti.

Girişte means at the entrance, on entry, or at check-in, depending on context.

Breakdown:

• giriş = entrance, entry, check-in
• -te = in / at / on

In a sentence about paying a fee, girişte often means something like:

• upon entry
• at check-in
• when entering

So it may refer to the moment of entry, not only the physical doorway.

Because the locative ending changes form according to consonant harmony and vowel harmony.

The locative can appear as:

• -de
• -da
• -te
• -ta

Since giriş ends in ş, which is a voiceless consonant, the suffix becomes -te.

So:

• giriş + de would be wrong
• giriş + te = girişte

Because ödendi is a passive verb form.

Breakdown:

• ödemek = to pay
• ödenmek = to be paid
• ödendi = was paid

Turkish builds the passive inside the verb, so it does not need a separate word like English was.

That is why a single Turkish word, ödendi, corresponds to English was paid.

Exactly. Turkish often uses the passive when the doer is unknown, unimportant, or simply not being mentioned.

So this sentence focuses on:

• the fee
• when/where it was paid

but not on the person who paid it.

If Turkish wanted to say who paid it, it would usually switch to an active sentence.

It follows a very normal Turkish pattern:

• Kampçı ünitesinin gecelik ücreti = the subject phrase
• girişte = place/time expression
• ödendi = verb

So the structure is roughly:

• [subject] [adverbial] [verb]

Turkish very often puts the verb at the end, so this word order is natural and expected.

Because Turkish does not have a definite article like English the.

Definiteness is usually understood from:

• context
• word order
• possession structures
• case marking

So where English says the camper unit’s nightly fee, Turkish simply uses the noun phrase without a separate word for the.