Learn Hardcore Greek: Πίσω από την αγορά υπάρχει μια παλιά γέφυρα που περνάει πάνω από τον δρόμο. - Behind the market there is an old bridge that goes over the road.

You might hear πίσω στην αγορά or πίσω από την αγορά in different contexts, but to mean physical location behind an object, πίσω από is the standard pattern.

Could I say πίσω η αγορά or πίσω την αγορά without από?

No, that would be ungrammatical in standard Modern Greek.

To connect πίσω with a noun, you need a preposition:

πίσω από την αγορά ✅ correct
πίσω η αγορά ❌ incorrect
πίσω την αγορά ❌ incorrect

There are cases where πίσω can stand alone (e.g. Κοίτα πίσω! = Look behind!), but when you specify an object (behind the market), you use πίσω από + accusative.

Why is υπάρχει used instead of είναι?

Υπάρχει and είναι can both translate as there is in English, but they are not identical:

υπάρχει literally means exists / there is and is used to introduce or point out the existence of something:
- Πίσω από την αγορά υπάρχει μια παλιά γέφυρα.
  = Behind the market there is an old bridge.
είναι is the verb to be, often used to identify or describe:
- Η γέφυρα είναι παλιά. = The bridge is old.
- Εκεί είναι μια γέφυρα. = There is a bridge over there.

In this sentence you are saying there exists an old bridge behind the market, so υπάρχει is the most natural choice.

Could I say Υπάρχει μια παλιά γέφυρα πίσω από την αγορά? Is that still correct?

Yes, that is also correct:

Πίσω από την αγορά υπάρχει μια παλιά γέφυρα…
Υπάρχει μια παλιά γέφυρα πίσω από την αγορά…

Both are grammatical. Greek word order is relatively flexible. The original version puts πίσω από την αγορά at the beginning to emphasize the location first. The alternative version emphasizes the existence of the bridge first.

Meaning is essentially the same; it’s mostly a matter of emphasis and style.

What is the difference between μια and μία? Why is μια παλιά γέφυρα used here?

Μια and μία are the same word historically, but in modern usage there’s a practical difference:

μια = the indefinite article a / an (most common spelling in everyday Greek)
- μια παλιά γέφυρα = an old bridge
μία = usually stressed as the number “one”, or used when you want to strongly emphasize one (and not another):
- μία γέφυρα μόνο υπάρχει εδώ. = Only one bridge exists here.

In your sentence, the meaning is simply an old bridge, not one single bridge for contrast, so μια παλιά γέφυρα is the natural choice.

Why is the adjective in μια παλιά γέφυρα placed between the article and the noun?

The most common and neutral position for an adjective in Greek is:

article + adjective + noun

Examples:

μια παλιά γέφυρα = an old bridge
η μεγάλη αγορά = the big market

So μια παλιά γέφυρα follows the standard pattern: μια (article) + παλιά (adjective) + γέφυρα (noun).

You can also see the adjective after the noun, but that usually has a slightly different nuance or requires repeating the article (η γέφυρα η παλιά, more emphatic or stylistic). For a simple an old bridge, the form in your sentence is the normal one.

What is the function of που in γέφυρα που περνάει? Is it the same as the English that?

Yes, in this sentence που works as a relative pronoun, similar to that / which / who in English.

μια παλιά γέφυρα που περνάει πάνω από τον δρόμο
= an old bridge that goes over the road

In everyday Modern Greek, που is the most common way to introduce a relative clause:

ο άνθρωπος που είδα = the man that I saw
το σπίτι που μένω = the house (that) I live in

More formal options like ο οποίος, η οποία, το οποίο exist, but που is default in spoken and informal written Greek.

Note: που here is not the question word πού (where). They differ in accent and function.

What tense and person is περνάει, and what verb does it come from?

Περνάει is:

present tense
third person singular
from the verb περνάω / περνώ (to pass, to go across, to cross, to spend [time])

Conjugation (present, informal style) of περνάω:

εγώ περνάω / περνώ = I pass
εσύ περνάς = you pass
αυτός/αυτή/αυτό περνάει / περνά = he/she/it passes

So η γέφυρα περνάει πάνω από τον δρόμο literally means the bridge passes over the road → idiomatically, the bridge goes over / crosses the road.

You may also see περνά instead of περνάει; both are acceptable in modern usage, with περνάει sounding slightly more colloquial in some regions.

Why is it πάνω από τον δρόμο and not just πάνω τον δρόμο or πάνω δρόμου?

Πάνω means on / above, but when you want to say over/above something, you normally use:

πάνω από + accusative
→ πάνω από τον δρόμο = over the road / above the road

Structures:

πάνω (adverb, by itself):
- Κοίτα πάνω. = Look up / look above.
πάνω σε + accusative:
- πάνω στον δρόμο = on the road (physically on its surface)
πάνω από + accusative:
- πάνω από τον δρόμο = over / above the road (spanning it)

Πάνω τον δρόμο and πάνω δρόμου are not correct in standard Greek. You need a preposition (σε or από) and the noun in the accusative.

Why is it τον δρόμο but την αγορά and μια γέφυρα? What are the genders here?

Greek nouns have grammatical gender, which determines the article form:

η αγορά (feminine)
- accusative: την αγορά
η γέφυρα (feminine)
- accusative: τη(ν) γέφυρα (with μια here instead of the definite article)
ο δρόμος (masculine)
- accusative: τον δρόμο

So:

πίσω από την αγορά → αγορά is feminine → την
μια παλιά γέφυρα → γέφυρα is feminine → μια
πάνω από τον δρόμο → δρόμος is masculine → τον

Why is the present tense περνάει used for a bridge, which is not moving?

In English this is also common: The bridge *goes over the river, even though the bridge doesn’t literally move; it *extends over it.

Greek uses the same idea:

Η γέφυρα περνάει πάνω από τον δρόμο.
= literally: The bridge passes over the road.
= naturally: The bridge goes over / crosses the road.

The present tense in Greek here describes a permanent characteristic or structure, not an action happening right now. This is the normal way to describe things like roads, bridges, rivers, etc., in both Greek and English.