Ο δρόμος είναι ήσυχος τη νύχτα.

Ο is the definite article for masculine singular nouns in the nominative case. It corresponds to English “the”.

• Ο δρόμος = the road / the street
  Greek almost always uses an article with nouns, much more than English does, so you’ll see ο / η / το (the) very frequently.

δρόμος is a masculine noun, nominative singular.

Clues:

• The article ο marks it as masculine.
• Many masculine nouns end in -ος in the nominative singular.

So:

• ο δρόμος = the road (subject of the sentence)

Greek adjectives must agree with the noun in gender, number, and case.

• Noun: ο δρόμος → masculine, singular, nominative
• Adjective: ήσυχος → masculine, singular, nominative

Other forms of the same adjective:

• ήσυχος (masc.) – δρόμος
• ήσυχη (fem.) – πόλη (city) → η πόλη είναι ήσυχη
• ήσυχο (neuter) – χωριό (village) → το χωριό είναι ήσυχο

Yes, ήσυχος can mean both:

• quiet / not noisy
• calm / not troubled

In this sentence, Ο δρόμος είναι ήσυχος τη νύχτα, it mainly means:

• The road is quiet at night (little traffic, little noise)

If you wanted “calm” in a more emotional sense about a person, you might also see ήρεμος, but ήσυχος is very common for “quiet street / quiet neighborhood / quiet person”.

τη and την are both forms of the feminine accusative singular article (the = “την/τη”).

Modern spelling and usage often drop the final -ν before many consonants. So:

• την → τη before some consonants, including ν in everyday writing.

So:

• τη νύχτα and την νύχτα are both understandable;
• τη νύχτα is very common in modern texts and speech.

Functionally, it’s the same article: (την) νύχτα = “the night”.

In Greek, time expressions are very often put in the accusative case without a preposition to mean “at / on / in (time)”.

So:

• τη νύχτα (accusative) → literally “the night”, but used as “at night”
• την Κυριακή → “on Sunday”
• κάθε μέρα → “every day”

You could say τη νύχτα with σε (e.g. τη νύχτα, στον δρόμο…), but when you just mean when (the time), accusative alone is the normal pattern.

• τη – definite article, feminine, singular, accusative (the)
• νύχτα – noun, feminine, singular, accusative (night)

Together: τη νύχτα = “the night” used as a time expression → “at night”.

The word order is flexible in Greek. All of these are grammatically correct:

• Ο δρόμος είναι ήσυχος τη νύχτα.
• Τη νύχτα ο δρόμος είναι ήσυχος.
• Ο δρόμος τη νύχτα είναι ήσυχος.

The basic neutral order here is subject–verb–complement–time:
Ο δρόμος (subject) είναι (verb) ήσυχος (complement) τη νύχτα (time).

Moving τη νύχτα to the front (or earlier in the sentence) just adds a bit of emphasis on “at night”.

Approximate phonetic transcription (Modern Greek):

• Ο δρόμος → [o ˈðromos]
  
  • δ like th in this
• είναι → [ˈine]
  
  • pronounced “íne” (EE-neh)
• ήσυχος → [ˈisixos]
  
  • both ή and υ here sound like ee
• τη νύχτα → [ti ˈnixta]
  
  • χ is a voiceless sound like the ch in German Bach or Scottish loch

Full sentence:
[o ˈðromos ˈine ˈisixos ti ˈnixta]

• ο δρόμος – “the road / street / way” (singular)
• οι δρόμοι – “the roads / streets” (plural)
• η οδός – also “street/road”, but:
  • More formal and used mainly in street names:
    
    • Οδός Πατησίων = Patission Street

In everyday speech, you’ll mostly use δρόμος / δρόμοι.