Learn Hardcore Greek: Η συμμαθήτριά μου πάντα μάζευε τα στυλό της στην κασετίνα και έλεγχε δύο φορές αν είχε γράψει το όνομά της. - My female classmate always gathered her pens into the pencil case and checked twice if she had written her name.

τρια without διαλυτικά would tend to be pronounced as one syllable -τρα /-tria/.
With τρϊα (written τριά), it is pronounced as -τρι-ά, two syllables.

So συμμαθήτριά is pronounced roughly sym-ma-thí-tri-a, not sym-ma-thí-tria in four syllables. The διαλυτικά simply tell you to “break” the vowel combination apart into two sounds.

Why is the stress on the last syllable in συμμαθήτριά μου and όνομά της, not where I usually see it in συμμαθήτρια / όνομα?

This is because of a rule about enclitic pronouns (like μου, σου, του, της) in Greek.

Basic forms:
- η συμμαθήτρια (accent on -μή-)
- το όνομα (accent on -ό-)

These are proparoxytone words (accent on the third syllable from the end).

When you add an enclitic like μου or της, Greek adds a second accent on the last syllable of the main word:

η συμμαθήτρια → η συμμαθήτριά μου
το όνομα → το όνομά της

You do not stress the pronoun; you add an extra accent to the main word’s last syllable. This keeps the stress within the last three syllables of the whole phrase, which Greek requires.

Why is μου placed after the noun (η συμμαθήτριά μου) instead of before it like English “my classmate”?

In Greek, the weak (clitic) possessive pronouns normally come after the noun:

η συμμαθήτριά μου = my (female) classmate
το βιβλίο σου = your book
το σπίτι του = his house

The pattern is:

article + noun + clitic pronoun

You can express possession in other ways (e.g. η δική μου συμμαθήτρια), but in everyday speech the clitic after the noun is by far the most common and natural.

What tense is μάζευε, and why isn’t it μάζεψε here?

Μάζευε is the imperfect (past continuous/imperfective) of μαζεύω (to gather, to collect).

(αυτός/αυτή) μάζευε = he/she was collecting, used to collect

The imperfect in Greek describes:

habitual past actions
- Πάντα μάζευε τα στυλό της = She always used to gather her pens.
or ongoing past actions.

If you said μάζεψε, that’s the aorist (simple past), which sounds more like one completed event:

Πάντα μάζεψε τα στυλό της – feels wrong; “always” doesn’t match a single completed action.
Χθες μάζεψε τα στυλό της. = Yesterday she (once) gathered her pens.

So μάζευε fits here because it’s describing a repeated habit in the past, not a one‑off event.

Is it the same situation with έλεγχε? Why not έλεγξε?

Yes, it’s the same imperfect vs aorist contrast.

(αυτός/αυτή) έλεγχε (imperfect) = he/she was checking, used to check
(αυτός/αυτή) έλεγξε (aorist) = he/she checked (once, as a single whole action)

In the sentence:

…και έλεγχε δύο φορές αν είχε γράψει το όνομά της.
→ …and she would check twice whether she had written her name.

This is part of a past routine, so the imperfect έλεγχε is appropriate.
Έλεγξε δύο φορές would sound like you’re narrating a specific occasion: She (once) checked twice…

Why does στυλό look the same in singular and plural (το στυλό, τα στυλό)? Shouldn’t the plural end differently?

Στυλό is an indeclinable neuter noun, borrowed from French (stylo). Many foreign nouns in Greek:

keep the same form in all cases and numbers, especially if they end in -ο.

So you say:

το στυλό = the pen (singular)
τα στυλό = the pens (plural)
με το στυλό = with the pen
με τα στυλό = with the pens

The article (το / τα) and context tell you whether it’s singular or plural, not the ending of στυλό itself.

What exactly does της mean in τα στυλό της and το όνομά της? Is it “of her”, “her”, or something else?

Here της is the weak (clitic) genitive pronoun for 3rd person singular feminine. In English it usually translates as “her” or “of her”:

τα στυλό της = her pens / the pens of hers
το όνομά της = her name / the name of hers

A few points:

It is not an article here; it’s a pronoun.
Its form (της) does not change depending on what is possessed; the article and noun (το όνομα, τα στυλό) show the gender/number of the thing possessed.
Της can also mean “to her” / “of her” in other contexts, but here it’s clearly possessive.

In στην κασετίνα, what is στην? Is it one word or two? Why not just σε την κασετίνα?

Στην is the contracted form of σε + την.

σε = in, at, to (preposition)
την = feminine singular definite article in the accusative (the)

In everyday Greek, σε + την is almost always written and pronounced as στην:

στην κασετίνα = in the pencil case (feminine noun κασετίνα)

Similarly:

σε + τη → στη (when the ν is dropped)
σε + τον → στον
σε + το → στο

So στην is grammatically two things (preposition + article), but written as one contracted word in modern Greek.

Does αν here mean “if” or “that”? Could I use ότι or πως instead?

Here αν means “if / whether”:

…έλεγχε δύο φορές αν είχε γράψει το όνομά της.
→ …she checked twice *if she had written her name.*

You cannot replace αν with ότι or πως here:

ότι / πως introduce a “that‑clause”, a statement:
- Έλεγξε ότι είχε γράψει το όνομά της.
  = She checked (verified) *that she had written her name.* (different meaning)

With αν, she is verifying whether or not she has written it; it’s an indirect question / condition, not a simple statement. So αν is the correct conjunction in this sentence.

What tense is είχε γράψει, and why use that instead of έγραψε, έγραφε, or έχει γράψει?

Είχε γράψει is the pluperfect (past perfect) tense of γράφω.

It’s formed: είχε (imperfect of έχω) + γράψει (perfective stem).
είχε γράψει = she had written

We use the pluperfect to show that something was already completed before another past action:

First: She wrote her name.
Later (still in the past): She checked twice if she had written it.

That sequence is:

είχε γράψει (had written) → earlier
έλεγχε (was checking) → later reference point in the past.

Other choices:

έγραψε = (she) wrote (simple past), doesn’t clearly say it was already done before the checking.
έγραφε = (she) was writing / used to write, suggests ongoing or habitual writing, not a completed act.
έχει γράψει = (she) has written, present perfect; it connects the action to the present, so it doesn’t fit a fully past narrative here.

So είχε γράψει correctly gives the idea “she had (already) written her name” at the time when she checked.

Why is it το όνομά της with το (neuter) if the person is female? Shouldn’t it agree with της?

In Greek, the article and adjective agreement goes with the noun, not the possessor.

το όνομα is a neuter noun.
So its article must be neuter: το όνομα (the name).
Adding possession: το όνομά της = her name.

The pronoun της indicates that the name belongs to a woman, but it does not change the gender of όνομα. So you always say:

το όνομά μου – my name
το όνομά σου – your name
το όνομά του/της/μας/σας/τους – anyone’s name; το stays neuter because όνομα is neuter.

Can της in this sentence refer to someone else, or must it refer to “my classmate”?

By itself, της can refer to any female person previously known from context. In this single isolated sentence, the most natural interpretation is that της refers back to η συμμαθήτριά μου (my classmate):

She gathered her pens…
She checked if she had written her name.

However, in a longer context, της could in principle refer to another woman mentioned earlier. Greek relies heavily on context for pronoun reference; there’s no special form to force it to mean “her own” vs “another woman’s” name the way some languages do.

So:

In this stand‑alone sentence: almost certainly her own.
In a full paragraph: you’d use context or add clarification, e.g. το δικό της όνομα (her own name) if you needed to stress that.

Where can I put πάντα in this sentence? Is πάντα μάζευε the only correct option?

Πάντα (always) is fairly flexible in Greek word order. All of these are possible:

Η συμμαθήτριά μου πάντα μάζευε τα στυλό της…
Η συμμαθήτριά μου μάζευε πάντα τα στυλό της…
Πάντα η συμμαθήτριά μου μάζευε τα στυλό της… (more emphatic)

They all mean roughly the same thing: My classmate always used to gather her pens…
The most neutral and common in everyday speech is what you see in the sentence:

Η συμμαθήτριά μου πάντα μάζευε τα στυλό της…

Moving πάντα can slightly shift emphasis (e.g. stressing “it was always her who did that” vs “she always did that action”), but grammatically the adverb can appear before or after the verb, or at the start of the clause.

Why is the noun for “classmate” feminine συμμαθήτρια here, and how would it look in masculine?

Greek marks gender on nouns, so there are usually different forms for male and female persons.

ο συμμαθητής = the (male) classmate
η συμμαθήτρια = the (female) classmate

In your sentence we have:

Η συμμαθήτριά μου…
→ the accent‑shifted form of η συμμαθήτρια plus μου.

This tells us explicitly that the classmate being talked about is female. If it were a male classmate, you would say:

Ο συμμαθητής μου πάντα μάζευε τα στυλό του…