Οι πεζοί περιμένουν στη διάβαση μέχρι να σταματήσουν τα αυτοκίνητα.

Pedestrians wait at the crosswalk until the cars stop.

Breakdown of Οι πεζοί περιμένουν στη διάβαση μέχρι να σταματήσουν τα αυτοκίνητα.

• σε: at
• περιμένω: to wait
• το αυτοκίνητο: the car
• σταματάω: to stop
• μέχρι να: until
• ο πεζός: the pedestrian
• η διάβαση: the crosswalk

Questions & Answers about Οι πεζοί περιμένουν στη διάβαση μέχρι να σταματήσουν τα αυτοκίνητα.

What do Οι and πεζοί each mean, and why is it Οι πεζοί and not something like Τα πεζοί?

Οι is the definite article the for masculine plural nouns in the nominative case.

πεζοί is the masculine plural nominative form of πεζός, which literally means on foot or pedestrian. In modern Greek, πεζοί is very commonly used as a noun meaning pedestrians.

So:

• ο πεζός = the pedestrian (masculine singular)
• οι πεζοί = the pedestrians (masculine plural)

We use Οι (masculine plural) because πεζοί is grammatically masculine plural.
Τα is the article for neuter plural nouns, so Τα πεζοί would be ungrammatical.

Is πεζοί an adjective or a noun here?

Grammatically, πεζός is an adjective meaning on foot, pedestrian, walking, as opposed to mounted or in a vehicle.

However, in this sentence πεζοί is used as a substantivized adjective—that is, an adjective functioning as a noun. This is very common in Greek.

So:

• As an adjective: πεζός στρατιώτης = infantry soldier (lit. on-foot soldier)
• As a noun: οι πεζοί = the pedestrians

In Οι πεζοί περιμένουν…, πεζοί is acting as a noun: the pedestrians.

What tense and person is περιμένουν, and how does it relate to περιμένω?

περιμένουν is:

• verb: περιμένω (to wait)
• tense/aspect: present (imperfective)
• person/number: 3rd person plural (they)

Forms:

• περιμένω = I wait
• περιμένεις = you (sg.) wait
• περιμένει = he/she/it waits
• περιμένουμε = we wait
• περιμένετε = you (pl.) wait
• περιμένουν(ε) = they wait

So in Οι πεζοί περιμένουν…, περιμένουν means they are waiting / they wait, agreeing with Οι πεζοί (they).

What exactly does στη διάβαση mean, and why is διάβαση in that form?

στη διάβαση literally means at the crossing or at the crosswalk.

Breakdown:

• σε = at / in / on (a very general preposition)
• τη = the (feminine singular accusative article)
• διάβαση = crossing, crosswalk (feminine noun)

In everyday speech and writing, σε + τη contracts to στη:

• σε τη διάβαση → στη διάβαση

Why is διάβαση in that form?

• The dictionary form is η διάβαση (nominative).
• After σε, Greek uses the accusative case, so we get τη(ν) διάβαση.
• For this noun, nominative and accusative singular happen to look the same: διάβαση.

So στη διάβαση = σε + τη + διάβαση = at the crossing.

Why is it στη διάβαση and not στην διάβαση with an extra ν?

στη is originally σε + τη(ν). The final -ν of την is often dropped in front of certain consonants.

The ν is usually kept:

• before vowels
• before π, τ, κ, μπ, ντ, γκ, ξ, ψ

It is often dropped before most other consonants, including δ. So:

• στη διάβαση is standard and very common.
• στην διάβαση is also possible in speech (and some writers might keep the ν for clarity or style), but στη διάβαση is what you will most often see.

Both are understandable; στη διάβαση is the normal spelling.

What does μέχρι mean on its own, and what is the difference between μέχρι and μέχρι να?

μέχρι on its own can be:

• a preposition: μέχρι το σχολείο = up to / as far as the school
• a conjunction of time: Θα περιμένω μέχρι τις πέντε. = I’ll wait until five.

When followed directly by a noun or time expression, it behaves like a preposition:

• μέχρι τη διάβαση = up to the crossing
• μέχρι τις 5 = until 5 o’clock

When followed by να + verb (subjunctive), it introduces a time clause about an event:

• μέχρι να σταματήσουν τα αυτοκίνητα = until the cars stop

So:

• μέχρι + noun/time → up to / until [point in space or time]
• μέχρι να + verb → until [something happens]

Why is σταματήσουν used here, and what form is it?

σταματήσουν is:

• verb: σταματάω / σταματώ (to stop)
• mood: subjunctive
• aspect: aorist (single, complete event)
• person/number: 3rd person plural

The form is built with the aorist stem σταματήσ- plus plural subjunctive ending -ουν(ε).

We use σταματήσουν because:

• μέχρι να is followed by the subjunctive in Greek.
• The aorist subjunctive describes a single future event that will be completed: the moment when the cars stop.

So μέχρι να σταματήσουν τα αυτοκίνητα = until the cars (have) stopped / until the cars stop (once).

Why is the subjunctive (σταματήσουν) used after μέχρι να, instead of something like σταματάνε?

In modern Greek, after να, ας, για να, πριν να, μέχρι να and similar particles, you generally use the subjunctive (with endings like -ω, -εις, -ει, -ουμε, -ετε, -ουν(ε) based on the subjunctive stem).

So:

• μέχρι να σταματήσουν τα αυτοκίνητα (correct)
• ✗ μέχρι να σταματάνε τα αυτοκίνητα (ungrammatical in standard Greek as a finite clause)

You could theoretically form a present (imperfective) subjunctive (μέχρι να σταματάνε), but in actual usage, with μέχρι να referring to a single future point, Greek strongly prefers the aorist subjunctive (σταματήσουν) to express the completion of that event.

Thus, the structure is:

• μέχρι να + aorist subjunctive = until [something happens/gets finished].

What is the function of τα αυτοκίνητα here, and how do I know its case if nominative and accusative look the same?

τα αυτοκίνητα means the cars.

Formally:

• article: τα (neuter plural, nominative or accusative)
• noun: αυτοκίνητα (neuter plural, nominative or accusative of το αυτοκίνητο)

In neuter plural, nominative and accusative are identical in form.
So to know the case, you look at the role in the sentence:

In μέχρι να σταματήσουν τα αυτοκίνητα:

• σταματήσουν is an intransitive verb here (to stop by themselves, not to stop something).
• The doer of the action (subject) is τα αυτοκίνητα.

So:

• grammatically, τα αυτοκίνητα is nominative plural, the subject of σταματήσουν.
• it just looks like accusative because neuter nominative = neuter accusative in form.

Context and verb type tell you it is the subject.

Can the word order of the sentence change, for example can τα αυτοκίνητα come earlier?

Yes. Greek word order is relatively flexible because roles are mostly marked by endings (cases, verb agreement), not by position.

The original:

• Οι πεζοί περιμένουν στη διάβαση μέχρι να σταματήσουν τα αυτοκίνητα.

Possible variations (all grammatical, with slight changes of emphasis):

• Οι πεζοί περιμένουν μέχρι να σταματήσουν τα αυτοκίνητα στη διάβαση.
  (Now στη διάβαση could sound more connected to σταματήσουν, i.e. “until the cars stop at the crossing”.)

• Οι πεζοί, μέχρι να σταματήσουν τα αυτοκίνητα, περιμένουν στη διάβαση.
  (More emphasis on the until the cars stop condition.)

• Μέχρι να σταματήσουν τα αυτοκίνητα, οι πεζοί περιμένουν στη διάβαση.
  (Emphasis on the time clause; “Until the cars stop, the pedestrians wait at the crossing.”)

You generally keep:

• Οι πεζοί close to περιμένουν (subject + verb).
• τα αυτοκίνητα close to σταματήσουν (subject of that verb).

If you moved τα αυτοκίνητα too far away, it would sound odd or confusing.

Is there any difference in meaning between μέχρι να σταματήσουν τα αυτοκίνητα and something like ώσπου να σταματήσουν τα αυτοκίνητα?

μέχρι να and ώσπου να are very close in meaning when they introduce a time clause with the subjunctive:

• μέχρι να σταματήσουν τα αυτοκίνητα
• ώσπου να σταματήσουν τα αυτοκίνητα

Both mean until the cars stop.

Nuances:

• μέχρι να is slightly more neutral and very common in both speech and writing.
• ώσπου να can sound a bit more colloquial or literary depending on context and region, but it is also standard.

In your sentence, you can safely replace μέχρι να with ώσπου να without changing the basic meaning.