Στο πανεπιστήμιο η αδερφή μου σπουδάζει μαθηματικά, αλλά εγώ προτιμώ τη βιολογία.

At the university my sister studies mathematics, but I prefer biology.

Breakdown of Στο πανεπιστήμιο η αδερφή μου σπουδάζει μαθηματικά, αλλά εγώ προτιμώ τη βιολογία.

• εγώ: I
• μου: my
• αλλά: but
• σε: at
• προτιμάω: to prefer
• το πανεπιστήμιο: the university
• η αδερφή: the sister
• σπουδάζω: to study
• τα μαθηματικά: the mathematics
• η βιολογία: the biology

Questions & Answers about Στο πανεπιστήμιο η αδερφή μου σπουδάζει μαθηματικά, αλλά εγώ προτιμώ τη βιολογία.

What does στο mean here, and why isn’t it written as two separate words?

Στο is a contraction of σε + το.

• σε = in / at / to
• το = the (neuter, singular, nominative/accusative article)

So στο πανεπιστήμιο literally = σε το πανεπιστήμιο = at the university.

In modern Greek, σε + τον / την / το very often contract:

• σε + τον → στον
• σε + την → στη(ν)
• σε + το → στο

That’s why you see στο πανεπιστήμιο, not σε το πανεπιστήμιο.

Why do we need the article η before αδερφή?

Η is the feminine singular definite article: η = the (for feminine, nominative).

In Greek, nouns are usually used with the definite article much more than in English, especially when you talk about specific people:

• η αδερφή μου = my sister (literally: the sister my)

Leaving out the article (αδερφή μου) is possible but sounds more informal or less standard in this kind of sentence. For “my X” in Greek, the most neutral pattern is:

η/ο/το + noun + μου
η αδερφή μου – my sister
ο αδερφός μου – my brother
το παιδί μου – my child

Why is μου placed after αδερφή instead of before it, like in English (my sister)?

Μου is a weak possessive pronoun (technically, an enclitic). These weak possessives:

• do not stand alone
• usually come after the noun they modify
• don’t need a preposition

So:

• η αδερφή μου = my sister (literally: the sister my)
• το βιβλίο μου = my book
• ο φίλος μου = my friend

If you want to emphasize my (own), you can use the strong possessive with δικός/δική/δικό:

• η δική μου αδερφή – my own sister
• το δικό μου βιβλίο – my own book

What grammatical form is η αδερφή μου in? Which case is it?

Η αδερφή μου is in the nominative case, because it is the subject of the verb σπουδάζει (studies).

• η αδερφή – nominative singular feminine (subject form)
• την αδερφή – accusative singular feminine (object form)

In the sentence:

Η αδερφή μου σπουδάζει μαθηματικά
My sister studies mathematics

• η αδερφή μου = subject → nominative
• μαθηματικά = object of the verb → (formally) accusative plural neuter, but nominative and accusative neuter plural look the same.

What exactly does σπουδάζει mean, and how is it different from just “studies” in English?

Σπουδάζει is the 3rd person singular present of σπουδάζω.

• σπουδάζω = to study (as a field of study, at a university)

It refers specifically to formal, often higher education:

• Σπουδάζω νομική. – I study law (at university).
• Σπουδάζει ιατρική. – She/He studies medicine.

It is not used for everyday “studying” a lesson the way English uses “study”:

• I’m studying for the exam. → Διαβάζω για τις εξετάσεις. (not: σπουδάζω)

So in your sentence, σπουδάζει μαθηματικά means she is majoring in / doing a degree in mathematics, not just “doing her homework in maths tonight”.

Why is μαθηματικά in the plural?

Μαθηματικά is grammatically neuter plural (η/το → τα, but here already plural), but it refers to the subject mathematics as a whole.

Many languages treat “mathematics” as plural grammatically. Greek does it too:

• μαθηματικά – mathematics
• Κάνω μαθηματικά. – I do maths.
• Μου αρέσουν τα μαθηματικά. – I like mathematics. (verb in plural: αρέσουν)

So the plural is simply the normal form of the word when you talk about the subject “maths”.

Why is there no article before μαθηματικά, but there is one before βιολογία (τη βιολογία)?

Both patterns are possible in Greek with school subjects:

• σπουδάζω μαθηματικά
• σπουδάζω τα μαθηματικά

and

• προτιμώ βιολογία
• προτιμώ τη βιολογία

In your sentence, we have:

• σπουδάζει μαθηματικά – no article
• προτιμώ τη βιολογία – with article

Some tendencies that help explain this:

1. When a subject is the field of study in general, the article is often omitted:

   • Σπουδάζω μαθηματικά / ιατρική / φιλολογία.

2. When the subject is a direct object of verbs like “like”, “prefer”, using the article is very common and feels natural, almost like pointing to a specific option:

   • Προτιμώ τη βιολογία (από τα μαθηματικά). – I prefer biology (to mathematics).
   • Μου αρέσει η βιολογία.

You could also say προτιμώ βιολογία; it would still be correct, just a bit more bare/neutral. The article often adds that feeling of “this particular subject as an option”.

Why is it τη βιολογία and not η βιολογία in this sentence?

Here we see accusative vs nominative:

• η βιολογία – nominative singular feminine (subject form)
• τη βιολογία – accusative singular feminine (object form)

In:

… αλλά εγώ προτιμώ τη βιολογία.

• εγώ = subject → nominative
• τη βιολογία = direct object of προτιμώ → accusative

If βιολογία were the subject, you’d use η:

• Η βιολογία είναι ενδιαφέρουσα. – Biology is interesting.

What form of the verb is προτιμώ, and does it come from προτιμάω?

Yes. Προτιμώ is the 1st person singular present of the verb προτιμώ / προτιμάω (to prefer).

This verb belongs to a group where there are often two parallel present forms:

• προτιμώ and προτιμάω – I prefer
• αγαπώ and αγαπάω – I love
• μιλώ and μιλάω – I speak

In everyday speech, προτιμώ is slightly more common and a bit “neater”; προτιμάω is also correct, just a bit more colloquial-sounding in many contexts.

So:

• εγώ προτιμώ – I prefer
• εσύ προτιμάς – you prefer
• αυτός/αυτή/αυτό προτιμά – he/she/it prefers
• etc.

Why is εγώ explicitly stated? I thought Greek often drops subject pronouns.

Greek does usually omit subject pronouns, because the verb ending already shows the person:

• Προτιμώ τη βιολογία. – I prefer biology. (subject “I” understood)

But here we have contrast:

… η αδερφή μου σπουδάζει μαθηματικά, αλλά εγώ προτιμώ τη βιολογία.
… my sister studies mathematics, but I prefer biology.

Using εγώ:

• emphasizes the contrast between η αδερφή μου and εγώ
• corresponds to English stress: but *I prefer biology.*

If you omit εγώ:

• … σπουδάζει μαθηματικά, αλλά προτιμώ τη βιολογία.

it’s still correct, just slightly less emphatic.

Why does the sentence start with Στο πανεπιστήμιο? Could we say Η αδερφή μου στο πανεπιστήμιο σπουδάζει μαθηματικά instead?

Yes, you can change the word order; Greek is quite flexible. All of these are possible:

1. Στο πανεπιστήμιο η αδερφή μου σπουδάζει μαθηματικά…
2. Η αδερφή μου σπουδάζει μαθηματικά στο πανεπιστήμιο…
3. Η αδερφή μου στο πανεπιστήμιο σπουδάζει μαθηματικά… (less neutral, more marked)

Differences are about focus:

• Starting with Στο πανεπιστήμιο highlights the setting: At university, my sister studies mathematics…
• Starting with Η αδερφή μου highlights the person: My sister, at university, studies mathematics…

The version you have is very natural and slightly emphasizes the place (university life) as context.

What does αλλά mean here, and how is it different from και or όμως?

Αλλά means but; it introduces a contrast or opposition:

• Σπουδάζει μαθηματικά, αλλά εγώ προτιμώ τη βιολογία.
  She studies mathematics, but I prefer biology.

Compare:

• και = and (adds, not contrasts)
  
  • Σπουδάζει μαθηματικά και προτιμά τη βιολογία. – She studies mathematics and prefers biology.
• όμως = however / though
  
  • Σπουδάζει μαθηματικά. Εγώ όμως προτιμώ τη βιολογία. – She studies maths. I, however, prefer biology.

In your sentence, αλλά is the natural choice because we want a single sentence with a clear but-type contrast between the sister and the speaker.