Learn Hardcore Greek: Αν η πόλη είναι μακριά, θα έρθω αύριο. - If the city is far, I will come tomorrow.

It’s a real (neutral) future condition. Greek typically uses the present indicative in the if‑clause to state a possible situation (Αν η πόλη είναι μακριά) and then uses θα + simple future in the main clause (θα έρθω) for the resulting action. The choice of simple future here (see below) presents a single, complete future event (coming tomorrow).

Why not say αν θα είναι or αν θα έρθω?

In standard Greek you don’t use θα in the conditional if‑clause. You say:

Αν η πόλη είναι μακριά, θα έρθω αύριο. Use αν + θα only in indirect yes/no questions (not conditions), e.g. Δεν ξέρω αν θα έρθω (I don’t know if I will come).

What’s the difference between αν, εάν, and άμα?

αν: the default everyday word for if.
εάν: more formal/literary; fully interchangeable with αν in meaning.
άμα: colloquial/informal for if/when, common in speech. Your sentence would also be fine as Άμα η πόλη είναι μακριά, θα έρθω αύριο.

Can I swap the clause order? What about the comma?

Yes. Both are fine:

Αν η πόλη είναι μακριά, θα έρθω αύριο. (If‑clause first → comma required.)
Θα έρθω αύριο αν η πόλη είναι μακριά. (Main clause first → usually no comma.)

Where can αύριο go? Does word order change the meaning?

It’s flexible:

Θα έρθω αύριο. (Neutral.)
Αύριο θα έρθω. (Slight emphasis on tomorrow.)
Θα έρθω αύριο, αν… / Αν…, θα έρθω αύριο. Meaning stays the same; fronting Αύριο adds focus to that time.

Why θα έρθω and not θα έρχομαι?

θα έρθω = simple (punctual) future: a single arrival tomorrow.
θα έρχομαι = future continuous: repeated/habitual or ongoing coming (e.g., I will be coming every week). With a one‑off time like αύριο, use θα έρθω.

What exactly is έρθω? Are θα ’ρθω or θα έλθω also correct?

έρθω is the aorist subjunctive of έρχομαι used after θα to form the simple future.
θα ’ρθω is a very common spoken contraction (elision of the initial vowel): perfectly natural.
θα έλθω is a more formal/conservative variant; fine in writing or formal speech.

Can I use μακρινή instead of μακριά? Any nuance?

μακριά is an adverb meaning far (away) and is the usual choice with είμαι for physical distance: Η πόλη είναι μακριά.
μακρινή is an adjective meaning distant; Η πόλη είναι μακρινή sounds like describing the city as a distant one by nature/characterization. You can intensify with πολύ: πολύ μακριά.

Do I need to say μακριά από… to be complete?

Not necessarily. Η πόλη είναι μακριά stands on its own. If you want to specify the reference point, add από:

Η πόλη είναι μακριά από εδώ/από εμένα/από την Αθήνα.

Any common spelling or pronunciation pitfalls in this sentence?

Αν has no accent (don’t write άν in Modern Greek).
η πόλη: η (no accent) is the feminine article; don’t confuse with ή = or. πόλη (city) is different from πολύ (very/much).
μακριά is the standard spelling; μακρυά is older/less standard.
είναι is spelled with ει; in fast speech you may hear είν’ (elision).
έρθω stress stays on the first syllable. You’ll often hear θα ’ρθω; pronounce the cluster ρθ as r + th (th as in English thin).
Gender note: πόλη is feminine, hence η πόλη.