Learn Hardcore Greek: Η αδερφή του προτιμάει το μπάσκετ και παίζει σε άλλη ομάδα. - His sister prefers basketball and plays on another team.

This article + noun + του/της/τους pattern is normal and is the standard way to say his/her/their X when the noun is the subject. You do not say του η αδερφή or η του αδερφή in modern Greek; η αδερφή του is the correct fixed order.

Does του mean “his” or “her”? How do I know whose sister it is?

του is the genitive form of the masculine pronoun αυτός (he), so its core meaning is “of him / his”.

However, in real use, του can also refer to:

a grammatically masculine noun (e.g. του Κώστα = of Kostas),
a masculine noun that represents a woman’s name if the name is in masculine form (less common),
or contextually “their (masc./neut.)” in some constructions.

To say her sister, Greek would normally use:

η αδερφή της = her sister

So without further context, η αδερφή του is naturally understood as his sister (or “the sister of some masculine person”). The context of the conversation tells you whose του is meant.

Why is there a definite article η before αδερφή? In English I say “his sister”, not “the his sister”.

Greek uses the definite article in many places where English does not:

Kinship terms with a possessive pronoun:
- η μητέρα μου = my mother
- ο πατέρας σου = your father
- η αδερφή του = his sister

The article agrees with the noun:

η αδερφή: η is feminine singular nominative (matches αδερφή).

So η αδερφή του is the normal, idiomatic way to say his sister, even though it literally looks like “the sister of him”.

I’ve seen αδερφή and αδελφή. Which one is correct?

Both forms exist:

αδερφή – more common in everyday, modern spelling; reflects current pronunciation.
αδελφή – more traditional / purist (katharevousa-influenced) spelling.

Pronunciation is essentially the same: [aðerˈfi] (or [aðelˈfi] for some speakers). In normal modern Greek writing, αδερφή is very frequent and perfectly correct.

What is the difference between προτιμά and προτιμάει? Here it says προτιμάει.

Both forms are correct present tense, 3rd person singular of προτιμάω / προτιμώ (to prefer):

αυτός/αυτή προτιμά
αυτός/αυτή προτιμάει

Meanings: identical – he/she prefers.

The -άει ending is slightly more colloquial / “fuller”; προτιμά is somewhat more neutral or formal. In everyday speech you’ll hear both. In writing, προτιμά is a bit more common.

Why is το μπάσκετ with a definite article? In English we just say “basketball”.

In Greek, names of sports usually take the neuter definite article:

το μπάσκετ – basketball
το ποδόσφαιρο – football/soccer
το τένις – tennis

So προτιμάει το μπάσκετ literally = he/she prefers *the basketball*, but this is just how standard Greek refers to the sport. In English we drop the article; in Greek you usually keep it.

Is μπάσκετ a normal Greek noun? How does it decline?

μπάσκετ is a loanword from English and is indeclinable:

το μπάσκετ (nominative)
του μπάσκετ (genitive)
το μπάσκετ (accusative)

The form μπάσκετ itself does not change; only the article or other surrounding words show the case.

Grammatically it is neuter singular: that’s why the article is το.

Who is the subject of παίζει? There is no pronoun like “she”.

The subject is still η αδερφή του (“his sister”).

Greek usually omits subject pronouns because the verb ending shows the person:

παίζει = he plays / she plays / it plays (3rd person singular)
In this sentence, the only logical 3rd person singular subject mentioned is η αδερφή του, so that’s who is playing.

So the meaning is:
His sister prefers basketball and (she) plays on another team.
You don’t repeat η αδερφή του or add αυτή unless you want specific emphasis or contrast.

What does σε άλλη ομάδα literally mean, and why is it often translated as “on another team”?

Literally:

σε = in / at / to / on (very general preposition)
άλλη = other / another (feminine)
ομάδα = team

So σε άλλη ομάδα = in another team / on another team / with another team.
English idiom prefers “on another team”, so translations use that.

In Greek, σε + accusative is the normal way to express being in/at/on a place or group:

σε ένα σχολείο – at a school
σε μια ομάδα – in/on a team

Why is it άλλη ομάδα and not άλλο ομάδα?

Adjectives in Greek must agree with the noun in:

gender (masculine/feminine/neuter)
number (singular/plural)
case (nominative/accusative/etc.)

ομάδα is feminine, singular, accusative, so the adjective must also be feminine singular accusative:

άλλος (masc.)
άλλη (fem.)
άλλο (neut.)

Therefore άλλη ομάδα is correct. άλλο ομάδα would be wrong because άλλο is neuter but ομάδα is feminine.

What tense are προτιμάει and παίζει? Do they describe a habit or something happening right now?

Both verbs are in the present tense, simple (imperfective) aspect:

(αυτή) προτιμάει – she prefers
(αυτή) παίζει – she plays / is playing

In Greek, the present tense typically describes:

Habitual / general facts
- Η αδερφή του προτιμάει το μπάσκετ = His sister (in general) prefers basketball.
Actions happening now, if the context makes that clear.

In this sentence, it is most naturally understood as describing her general preference and regular activity, not just something she’s doing only at this exact moment.

Can I change the word order, for example say Του η αδερφή προτιμάει το μπάσκετ?

No, that would sound wrong in modern Greek.

With a weak possessive pronoun like του, the normal order is:

[article] + [noun] + [possessive clitic]
- η αδερφή του, ο φίλος μου, το σπίτι μας

You cannot put του before η αδερφή in this construction.
You also wouldn’t normally separate the article from the noun.

So stick with Η αδερφή του προτιμάει το μπάσκετ…

How do you pronounce the whole sentence?

A practical phonetic approximation (Latin letters, stress marked) is:

I aderfí tu protimáei to básket ke pézi se áli omáda.

More precisely in IPA (one possible modern Greek pronunciation):

[i aðerˈfi tu protiˈmai to ˈbasket ce ˈpezi se ˈali oˈmaða]

Notes:

η / ι / υ / ει / οι often sound like [i].
μπ at the beginning of a word is pronounced [b].
δ is [ð], like th in this.
θ (not in this sentence, but related) is [θ], like th in think.

How would I say “She prefers basketball to football” using this verb?

You can use προτιμάω / προτιμώ with από:

Προτιμάει το μπάσκετ από το ποδόσφαιρο.
= She prefers basketball to football/soccer.

Structure:

προτιμάει
- [thing A]
  - από
    - [thing B]
Literally: She prefers the basketball from the football.