Learn Hardcore Greek: Κάθε βράδυ γράφω ένα μήνυμα στη φίλη μου. - Every night I write a message to my female friend.

Also, time expressions like κάθε βράδυ, κάθε μέρα normally use the accusative case, and here βράδυ (night) in the singular accusative happens to look the same as the nominative. That’s why the form is βράδυ, not βράδια.

Why is the verb γράφω and not something like a special form for “I am writing”?

Modern Greek has one present tense form, and it covers both:

English I write (habitual)
English I am writing (right now)

So γράφω can mean:

(I) write / I write – general habit
(I) am writing – right now

In this sentence, Κάθε βράδυ γράφω…, the phrase κάθε βράδυ shows it is a habitual action, so the natural translation is “Every night I write a message…”, but the Greek form γράφω is the same one you’d also use for “I am writing” in other contexts.

Could I say Εγώ γράφω instead of just γράφω?

Yes, you can say Εγώ γράφω (“I write / I am writing”), but in Greek the subject pronoun (εγώ, I) is usually dropped, because the verb ending already shows the person:

(Εγώ) γράφω = I write
(Εσύ) γράφεις = you write
(Αυτός/αυτή/αυτό) γράφει = he/she/it writes

You normally add εγώ only when you want to emphasize I (as opposed to someone else):

Εγώ γράφω το μήνυμα, όχι εσύ.
I am writing the message, not you.

In neutral sentences like Κάθε βράδυ γράφω…, leaving εγώ out is more natural.

Why is it ένα μήνυμα and not just μήνυμα or το μήνυμα?

Ένα is the indefinite article (a/an). Greek works similarly to English here:

ένα μήνυμα = a message
το μήνυμα = the message
plain μήνυμα is possible in some contexts, but it feels more like a bare noun (e.g. in headings, labels, or in certain idioms), not a normal sentence object.

In this sentence you are talking about a message you write each night, not a specific, known one, so ένα μήνυμα fits best.

What exactly is στη in στη φίλη μου?

Στη is a contracted form of:

σε (to, in, at) + τη(ν) (the, feminine singular accusative)

So:

σε + τη φίλη μου → στη φίλη μου

It literally means “to the friend (female) of mine”, i.e. to my (female) friend.

Greek no longer has a separate dative case, so “to someone” is usually expressed with σε + accusative, often contracted:

σε τον φίλο → στον φίλο (to the male friend)
σε τη φίλη → στη φίλη (to the female friend)
σε το παιδί → στο παιδί (to the child)

Why does Greek say στη φίλη μου (with “the”) when English just says “to my friend” without “the”?

Greek uses the definite article more often than English, especially before:

nouns with possessive pronouns (μου, σου, του, της, μας, σας, τους)
people’s roles and relationships

So:

στη φίλη μου literally: to the friend my
natural English: to my friend

Likewise:

ο αδελφός μου = (the) brother my → my brother
η μητέρα μου = (the) mother my → my mother

Leaving out the article here (σε φίλη μου) would sound wrong in normal modern Greek.

Why is it φίλη and not φίλος? Does φίλη mean “girlfriend”?

Greek nouns have grammatical gender.

ο φίλος = male friend (or boyfriend, depending on context)
η φίλη = female friend (or girlfriend, depending on context)

So στη φίλη μου means to my female friend (or to my girlfriend; it depends entirely on context).

If you wanted to my (male) friend, you’d say:

στον φίλο μου

Why does μου come after φίλη and not before, like “my friend”?

Greek possessive pronouns (my, your, his…) are clitics that normally come after the noun they modify:

η φίλη μου = my friend
ο αδελφός σου = your brother
το σπίτι μας = our house

So the pattern is:

article + noun + possessive

You don’t say μου φίλη for “my friend” in standard Greek; it must be η φίλη μου (or, with a preposition, στη φίλη μου).

Can I change the word order? Is Γράφω ένα μήνυμα κάθε βράδυ στη φίλη μου also correct?

Yes, Greek has flexible word order. All of these are grammatically correct and natural, with only slight shifts in emphasis:

Κάθε βράδυ γράφω ένα μήνυμα στη φίλη μου.
Γράφω ένα μήνυμα κάθε βράδυ στη φίλη μου.
Κάθε βράδυ στη φίλη μου γράφω ένα μήνυμα.

Putting κάθε βράδυ first makes the time more prominent.
If you put στη φίλη μου earlier, it can highlight who you’re writing to. But for everyday speech, all of them are fine, and the original order is very typical.

What is the difference between γράφω and γράψω?

They are different aspectual forms of the verb “to write”:

γράφω = present stem → used for present and imperfective aspect
- γράφω (I write / I am writing)
- έγραφα (I was writing / I used to write)
γράψω = aorist stem → used mainly in the subjunctive and future
- να γράψω (that I write / for me to write, one-time)
- θα γράψω (I will write, one-time)

In your sentence, you want a habitual action (“Every night I write…”), so Greek uses the present indicative: γράφω, not γράψω.

How is γράφω conjugated? What are the other forms like “you write”, “he writes”?

Γράφω is a regular -ω verb. In the present tense:

εγώ γράφω – I write / I am writing
εσύ γράφεις – you (singular) write
αυτός / αυτή / αυτό γράφει – he / she / it writes
εμείς γράφουμε – we write
εσείς γράφετε – you (plural / formal) write
αυτοί / αυτές / αυτά γράφουν(ε) – they write

So if you change the subject:

Κάθε βράδυ γράφουμε ένα μήνυμα στη φίλη μας.
Every night we write a message to our friend (female).

What’s the difference between γράφω ένα μήνυμα and στέλνω ένα μήνυμα?

γράφω ένα μήνυμα = I write a message (focus on composing it)
στέλνω ένα μήνυμα = I send a message (focus on sending; could be SMS, email, etc.)

Often, in real life, when people say they “send a message”, they’ll use στέλνω:

Κάθε βράδυ της στέλνω ένα μήνυμα.
Every night I send her a message.

Your original sentence is still perfectly correct; it just emphasizes the writing activity itself.

Why is στη sometimes written στην? When do you keep the final -ν?

Historically it’s στην (= σε + την). In modern writing, the final -ν is:

kept before vowels and certain consonants (κ, π, τ, ξ, ψ, μπ, ντ, γκ, τσ, τζ)
often dropped elsewhere in casual writing

So you may see:

στην Αθήνα (before vowel)
στην πόλη (before π)
στη γέφυρα (sometimes without ν before γ in everyday spelling)

Your στη φίλη μου is very common in contemporary usage, but στην φίλη μου is also possible and understood; the rule is not rigid in informal texts.