Learn Hardcore Greek: Η ξαδέρφη μου δουλεύει σε μουσείο και αγαπάει την τέχνη. - My cousin female works in a museum and loves art.

Η ξαδέρφη = the (female) cousin
Greek usually uses the article with family members, professions, etc., where English often drops it. So Η ξαδέρφη μου literally is “the cousin my”, but it means “my cousin” (female).

Why does μου (my) come after ξαδέρφη and not before, like in English?

In Greek, short possessive pronouns like μου (my), σου (your), του (his), της (her) usually come after the noun:

η ξαδέρφη μου = my cousin
το βιβλίο σου = your book
η δουλειά του = his job

They are unstressed (clitic) words and attach to the noun phrase.
You don’t normally say μου ξαδέρφη; that word order is wrong in standard modern Greek.

What is the difference between ξαδέρφη and ξάδερφος?

They are the feminine and masculine forms of cousin:

η ξαδέρφη = female cousin
ο ξάδερφος = male cousin

The article also changes:

η for feminine
ο for masculine

So:

Η ξαδέρφη μου δουλεύει… = My (female) cousin works…
Ο ξάδερφός μου δουλεύει… = My (male) cousin works…

I’ve also seen ξαδέλφη and ξάδελφος. Are those different words?

They are spelling/pronunciation variants of the same words:

ξαδέρφη / ξαδέλφη = female cousin
ξάδερφος / ξάδελφος = male cousin

The forms with -δέρφ- (ξαδέρφη, ξάδερφος) are more colloquial and very common in spoken Greek.
The forms with -δέλφ- (ξαδέλφη, ξάδελφος) are a bit more formal/literary.
Meaning and usage are the same; it’s a stylistic choice.

How is Η ξαδέρφη μου pronounced?

Roughly in English sounds:

Η = /i/ (like ee in see)
ξαδέρφη = /ksa-THER-fi/, but more accurately /ksaˈðerfi/
- ξ = /ks/ (like x in box)
- δ = voiced th as in this
- η at the end = /i/ (ee)

So the whole phrase is approximately: i ksa-DHER-fi mu
(using dh for the Greek δ).

Why is it δουλεύει and not something like δουλεύειε or δουλεύη?

Δουλεύει is the 3rd person singular, present tense of δουλεύω (to work):

(εγώ) δουλεύω = I work
(εσύ) δουλεύεις = you work
(αυτός/αυτή/αυτό) δουλεύει = he/she/it works

Modern Greek 3rd singular present for many verbs ends in -ει (spelled -ει, pronounced /i/).
So δουλεύει is the normal, correct form for “he/she works”.

What does σε μουσείο literally mean, and why is there no word for “a”?

Σε μουσείο literally is “in/at museum”.

Key points:

σε = in / at / to (general preposition of place/direction)
Greek doesn’t have a separate indefinite article “a” / “an” like English.
μουσείο without an article here is understood as “a museum”, not “the museum”.

So:

σε μουσείο = at a museum (non‑specific)
σε ένα μουσείο = at one (particular) museum (still “a museum”)
στο μουσείο (σε + το → στο) = at the museum (specific)

What is the difference between σε μουσείο and στο μουσείο?

Both use σε, but:

σε μουσείο: no article → “at a museum” (some museum, not specified)
σε + το μουσείο → στο μουσείο: with the definite article → “at the museum” (a known/specific museum)

So the original sentence suggests:

She works in a museum (her job type), not necessarily a particular museum already known in the conversation.

Why does Greek say αγαπάει and not just αγαπά? Are they different?

Both αγαπά and αγαπάει are correct and mean the same:

Both are 3rd person singular present of αγαπώ (to love):
- αγαπά = she loves
- αγαπάει = she loves

Differences:

αγαπά is a bit more formal/written.
αγαπάει sounds more colloquial/spoken and is very common in everyday speech.

You can use either. In many verbs of this type (μιλά / μιλάει, ρωτά / ρωτάει, etc.), the version with -ει feels slightly more informal or conversational.

Why do we say την τέχνη with “the”, even though English just says “loves art” without “the”?

Greek uses the definite article much more often than English.

την τέχνη = the art, but in many contexts it simply corresponds to English “art” in general.

So:

αγαπάει την τέχνη literally: she loves the art
Natural English: she loves art

Greek tends to use the article with:

abstract nouns (η μουσική, η λογοτεχνία, η τέχνη)
general concepts
when talking about things in general, not only specific ones.

So you almost always say:

Αγαπάω την μουσική. = I love music.
Αγαπάει την τέχνη. = She loves art.

Why is it την τέχνη and not η τέχνη, even though τέχνη is feminine?

Τέχνη is indeed a feminine noun, but its article changes with case.

η τέχνη → nominative (subject):
- Η τέχνη είναι σημαντική. = Art is important.
την τέχνη → accusative (direct object):
- Αγαπάει την τέχνη. = She loves art.

In our sentence:

την τέχνη is the object of the verb αγαπάει, so we must use την, not η.

Why do ξαδέρφη and τέχνη look the same in nominative and accusative?

Many feminine nouns ending in -η have the same form in singular nominative and accusative:

Nominative: η τέχνη, η ξαδέρφη
Accusative: την τέχνη, την ξαδέρφη

What changes is the article, not the noun ending:

η → nominative (subject)
την → accusative (object)

So to know the case, you pay attention to:

the article (η / την)
the role in the sentence (subject vs object)

Is the word order fixed? Could I say Η μου ξαδέρφη δουλεύει σε μουσείο?

You cannot say Η μου ξαδέρφη.

In Greek:

The usual order is [article] + [noun] + [possessive]:
- η ξαδέρφη μου, ο αδερφός σου, το σπίτι μας.
The possessive μου comes after the noun, not before it.

Word order in Greek is more flexible than English in many ways, but the position of these short possessives (μου, σου, του, της, μας, σας, τους) after the noun is very stable and should not be changed.