Η υπάλληλος ήταν πολύ ευγενική στη ρεσεψιόν, αλλά το ερωτηματολόγιο της έρευνας ήταν λίγο κουραστικό.

Because υπάλληλος is one of those Greek nouns that can be masculine or feminine with the same form.

• ο υπάλληλος = the male employee
• η υπάλληλος = the female employee

So here, the article η tells you it is feminine, and the adjective ευγενική confirms that too.

Greek adjectives must agree in gender, number, and case with the noun they describe.

Since η υπάλληλος is feminine singular, the adjective also has to be feminine singular:

• masculine: ευγενικός
• feminine: ευγενική
• neuter: ευγενικό

So η υπάλληλος ήταν πολύ ευγενική means the employee was very polite.

Because they are being used as predicate adjectives after the verb to be.

Compare:

• η ευγενική υπάλληλος = the polite employee
  (adjective directly attached to the noun)
• η υπάλληλος ήταν ευγενική = the employee was polite
  (adjective after ήταν)

The same applies to:

• το κουραστικό ερωτηματολόγιο = the tiring questionnaire
• το ερωτηματολόγιο ήταν κουραστικό = the questionnaire was tiring

Ήταν is the 3rd person singular imperfect of είμαι (to be).

It means was and is used for past states, descriptions, or ongoing situations in the past.

In this sentence, it describes two past states:

• the employee was polite
• the questionnaire was a bit tiring

Also, ήταν is the same form for he/she/it was.

Στη is the contracted form of σε τη.

• σε = in / at / to
• τη = the (feminine accusative singular)

So:

• σε τη ρεσεψιόν → στη ρεσεψιόν

Greek normally uses σε + accusative for location in expressions like at the reception.

Yes. Ρεσεψιόν is a very common loanword, especially in places like hotels, clinics, or offices.

It is widely understood and natural in everyday speech. A more native Greek alternative is υποδοχή.

So both can work, but ρεσεψιόν sounds especially natural in service-related contexts.

No, in της έρευνας, της is not the possessive pronoun her. It is the feminine singular genitive article, meaning of the.

So:

• η έρευνα = the survey
• της έρευνας = of the survey

Greek της can mean different things depending on context, so learners often confuse them. Here, because it is followed by a noun (έρευνας), it is clearly the article: of the survey.

Because Greek uses the genitive case to show relationships like of the survey.

Here:

• το ερωτηματολόγιο = the questionnaire
• της έρευνας = of the survey

Together:

• το ερωτηματολόγιο της έρευνας = the survey questionnaire / the questionnaire of the survey

The noun έρευνα changes to έρευνας because it is in the genitive singular.

Because it agrees with το ερωτηματολόγιο, which is neuter singular.

So the adjective must also be neuter singular:

• masculine: κουραστικός
• feminine: κουραστική
• neuter: κουραστικό

That is why Greek says:

• το ερωτηματολόγιο ήταν κουραστικό

Here λίγο means a little, a bit, or somewhat. It modifies the adjective κουραστικό.

So:

• λίγο κουραστικό = a little tiring / somewhat tiring

In this sentence, λίγο is functioning as an adverb, not as an adjective.

That is important because λίγο can also appear as part of the adjective λίγος, λίγη, λίγο (little / few), but here it simply means to a small degree.

Greek uses the definite article more often than English.

In this sentence you have:

• Η υπάλληλος
• στη ρεσεψιόν
• το ερωτηματολόγιο
• της έρευνας

In English, you might sometimes omit the, but in Greek the article is very often required with specific nouns. So even if it feels repetitive to an English speaker, it is normal Greek.