Learn Hardcore Greek: Η μαμά σου σού στέλνει μήνυμα κάθε μέρα.

The first σου after μαμά is the possessive clitic: η μαμά σου = your mom.
The second σού before the verb is the indirect object clitic: σού στέλνει = sends to you. Both are 2nd person singular, genitive clitics, but one is possessive and the other is an indirect object.

Why is the second one written with an accent (σού) here?

Monosyllabic clitics like μου/σου/του… are normally written without an accent. Writers often add an accent to the second one when two identical clitics appear close together, to make reading clearer and avoid confusion. Hence: Η μαμά σου σού στέλνει… This accent is a clarity convention; you’ll also see everything unaccented.

Is it wrong to write both as unaccented (Η μαμά σου σου στέλνει…)?

It’s not wrong. Many Greeks write Η μαμά σου σου στέλνει μήνυμα… without the extra accent. Adding the accent on the second (σού) is just a helpful convention in careful writing.

Where does the clitic pronoun go relative to the verb?

In ordinary statements: before the verb (proclitic): σού στέλνει.
With future/particles (θα/να/ας): before the verb: θα σου στείλει, να σου στείλει.
Negative commands (with μη(ν)): before the verb: Μην μου στείλεις.
Affirmative commands: after the verb (enclitic): Στείλε μου μήνυμα. So in your sentence (a statement), it must be before: σού στέλνει.

What’s the difference between σου and σε for “you”?

σου = genitive clitic, typically the indirect object (“to you”): Σου γράφω = I’m writing to you.
σε = accusative clitic, typically the direct object (“you”): Σε βλέπω = I see you. For emphasis/clarity, the strong forms εσένα / σε εσένα are used: Το έστειλα σε εσένα.

Do I need the article η before μαμά?

Yes. With kinship terms plus a possessive, Greek normally uses the definite article: η μαμά σου, ο πατέρας μου, η αδερφή του. Omitting it here would sound odd.

Do I need the word for “a” (ένα) before μήνυμα?

No. Σου στέλνει μήνυμα is natural and idiomatic. You can add ένα (σου στέλνει ένα μήνυμα) to stress “one single message,” but it isn’t required—especially with κάθε μέρα indicating habitual, one-per-day.

What cases are used in this sentence?

Η μαμά: nominative feminine singular (subject)
σου (after μαμά): genitive clitic (possessive “your”)
σού (before στέλνει): genitive clitic (indirect object “to you”)
μήνυμα: accusative neuter singular (direct object)
κάθε μέρα: accusative (time expression; κάθε is invariable)

Can I change the word order?

Yes, for emphasis or flow. Examples (all natural):

Κάθε μέρα η μαμά σου σού στέλνει μήνυμα. (focus on time)
Σου στέλνει μήνυμα η μαμά σου κάθε μέρα. (focus toward the pronoun/verb)
Η μαμά σου σού στέλνει κάθε μέρα μήνυμα. (slight focus on “every day”/object) Keep the clitic before the verb in statements.

What’s the difference between στέλνει and στείλει?

στέλνει: present tense (habitual/ongoing): “(she) sends/is sending.”
στείλει: aorist subjunctive stem, used after particles like να/ας or with θα for single, completed events:
- Να σου στείλει μήνυμα = to send you a message (once).
- Θα σου στείλει μήνυμα = will send you a message (once). For habitual future, Greek often uses θα σου στέλνει (“will be sending / probably sends”).

How do I pronounce the whole sentence?

Approximate IPA: [i maˈma su su ˈstelni ˈminima ˈkaθe ˈmera]
Notes:

η/ι/υ/ει/οι all sound like i.
σου = [su].
στέλνει = [ˈstelni] (the -ει is i).
θ in κάθε = th in “thin.”
Primary stresses: μα-ΜΑ, ΣΤΕΛ-, ΜΗ-, ΚΑ-, ΜΕ-.

Is there any nuance between κάθε μέρα, κάθε ημέρα, and καθημερινά?

κάθε μέρα: everyday speech, neutral.
κάθε ημέρα: more formal/literary.
καθημερινά: adverb “daily.”
All fit here: …σού στέλνει μήνυμα καθημερινά.

How do I say it with formal/plural “you”?

Use σας for both possessive and indirect object:

Η μαμά σας σάς στέλνει μήνυμα κάθε μέρα. Writers often accent the second σάς to disambiguate, just like σού above.

How do I make it negative?

Standard: Η μαμά σου δεν σου στέλνει μήνυμα κάθε μέρα.
With the clarity accent: Η μαμά σου δε(ν) σού στέλνει μήνυμα κάθε μέρα. Both are understood; many people simply write δεν.