Learn Hardcore Greek: Θα σας στείλω κάτι μετά. - I will send you polite/plural something later.

plural you (you all), or
formal singular you (polite “you” addressed to one person). Context decides which one is meant. Here it functions as an indirect object: “I will send something to you.”

Why is the verb στείλω and not στέλνω after θα?

Greek future uses aspect:

θα στείλω = simple future (a single, complete action: “I will send”).
θα στέλνω = future continuous/habitual (“I will be sending,” “I’ll keep sending”). So στείλω (aorist subjunctive form) is chosen for a one‑off future action.

How would I say this to one friend informally?

Use the informal singular clitic σου: Θα σου στείλω κάτι μετά.

Can the pronoun σας come after the verb?

Not in this construction. With finite verbs (present/past/future with θα), weak pronouns normally come before the verb: Θα σας στείλω…, not “Θα στείλω σας…”. They come after only with affirmative imperatives (e.g., Στείλτε μας κάτι “Send us something”).

How do I say “I’ll send it to you later”?

Θα σας το στείλω μετά/αργότερα.
Pronoun order rule: indirect object clitic before direct object clitic → σας το, not “το σας.” Change the direct object clitic to match gender/number of “it” if needed (τον/την/το).

Is μετά the best choice for “later”? How is it different from αργότερα?

Both are fine, but there’s a nuance:

μετά = “after(wards)/later” and also functions as a preposition with a noun: μετά (από) τη συνάντηση “after the meeting.”
αργότερα = “later” (more neutral for an unspecified later time).
In your sentence, either works; many speakers prefer αργότερα for “later (at some point).”

Can I move μετά to another position?

Yes. Natural options:

Μετά θα σας στείλω κάτι.
Θα σας στείλω κάτι μετά. Avoid: “Θα σας στείλω μετά κάτι” (sounds off). Position mainly affects emphasis, not meaning.

Can I omit κάτι (“something”)?

Usually no, unless the object is understood from context and replaced with a pronoun.

If the object is known: Θα σας το στείλω (μετά).
Without any object, Θα σας στείλω can mean “I’ll send you (somewhere),” which is a different meaning.

Can you break down the grammar of the sentence?

Θα: future particle.
σας: weak 2nd-person clitic (genitive), “to you.”
στείλω: 1st person singular aorist subjunctive of στέλνω, used with θα for the simple future.
κάτι: indefinite pronoun, “something.”
μετά: adverb, “later/afterwards.”

How do you pronounce it?

IPA: [θa sas ˈstilo ˈkati meˈta]
Roughly: “Tha sas STI-lo KA-ti me-TA.”
Notes: θ is like th in “think,” ει in στείλω sounds like “ee,” and the stress is on στεί-, κά-, and -τά.

Does θα mean “will” or “going to,” or both?

Both. Θα covers English “will/going to.” It also often marks probability in the present/past (e.g., Θα είσαι κουρασμένος = “You must be tired”). In your sentence it’s a straightforward future promise/intention.

How do I make it negative?

Use δεν and switch “something” to the negative polarity word τίποτα:

Δεν θα σας στείλω τίποτα μετά. = “I won’t send you anything later.”

Can I use a full pronoun instead of the clitic? Like “to you” with a preposition?

Yes, for emphasis: Θα στείλω κάτι σε εσάς (μετά).
You can also combine emphasis with clitic “doubling”: Σε εσάς θα σας στείλω κάτι.

Could μετά here mean “after you” (as in, after you in line)?

No. Alone, μετά means “later/afterwards.” To mean “after you,” you need a complement: μετά από εσάς (or μετά εσάς in more formal style). Example: Θα σας στείλω κάτι μετά από τη συνάντηση = “I’ll send you something after the meeting.”