Learn Hardcore Greek: Όλος ο κόσμος στο γραφείο είναι κουρασμένος σήμερα.

In everyday Greek, ο κόσμος often means “people”, not “planet Earth.”
So Όλος ο κόσμος in context usually means “everyone (all the people)” rather than “the entire world” in a global sense.

In this sentence, Όλος ο κόσμος στο γραφείο means “everyone in the office”.

Why is it Όλος ο κόσμος and not Όλοι ο κόσμος?

Because όλος has to agree in gender and number with κόσμος:

κόσμος is masculine singular.
The masculine singular form of “all/whole” is όλος.
The masculine plural form is όλοι.

So:

όλος ο κόσμος = the whole (masculine singular) world / all the people
όλοι = everyone / all (as a standalone pronoun, usually with a plural verb)

You could say:

Όλος ο κόσμος είναι κουρασμένος.
Όλοι είναι κουρασμένοι.

Both mean “everyone is tired,” but the structure is different.

If Όλος ο κόσμος means “everyone,” why is είναι not clearly plural?

The verb είναι is both 3rd person singular and 3rd person plural in Modern Greek. The form doesn’t change:

Αυτός είναι = he is
Αυτοί είναι = they are

In Όλος ο κόσμος είναι κουρασμένος, the grammar treats ο κόσμος as singular (the whole world / the whole group), so the adjective is singular (κουρασμένος), but the verb form είναι is the same whether you think of it as “is” or “are”.

So there is no visible difference on the verb; the singular vs plural feeling comes from the noun and adjective.

Why is the adjective κουρασμένος masculine singular? Aren’t we talking about many people, men and women?

In Greek, a predicate adjective (an adjective after είμαι) must agree with the grammatical subject, not with the real-world mix of people:

Subject: ο κόσμος → masculine, singular
So the adjective: κουρασμένος → masculine, singular

Even if o κόσμος includes men and women, you still match the gender and number of the word κόσμος, not the actual people.

If you changed the subject to a plural that refers directly to the people, the adjective would change too:

Όλοι στο γραφείο είναι κουρασμένοι σήμερα.
- Όλοι → masculine plural (default/mixed group)
- κουρασμένοι → masculine plural

So:

Όλος ο κόσμος … είναι κουρασμένος (singular)
Όλοι … είναι κουρασμένοι (plural)

Could I also say Όλοι στο γραφείο είναι κουρασμένοι σήμερα? What’s the difference?

Yes, that sentence is perfectly correct and very natural:

Όλος ο κόσμος στο γραφείο είναι κουρασμένος σήμερα.
Όλοι στο γραφείο είναι κουρασμένοι σήμερα.

Both mean “Everyone in the office is tired today.”

Nuance:

Όλος ο κόσμος is a bit more “everyone, the whole crowd”—it can sound slightly more vivid or emphatic.
Όλοι στο γραφείο is more straightforward: just “everyone at the office.”

Grammatically:

Όλος ο κόσμος (noun phrase) → singular, so κουρασμένος (singular)
Όλοι (pronoun) → plural, so κουρασμένοι (plural)

What exactly does ο κόσμος mean in modern Greek? Is it always “world”?

ο κόσμος has two main everyday meanings:

the world (like English “world”)
- Ο κόσμος αλλάζει. = The world is changing.
people / everyone / the public
- Ήρθε πολύς κόσμος. = A lot of people came.
- Ο κόσμος στο λεωφορείο ήταν κουρασμένος. = The people on the bus were tired.

In your sentence, Όλος ο κόσμος στο γραφείο clearly means “all the people in the office / everyone in the office,” not the planet. Context usually makes it clear.

What does στο γραφείο mean exactly? Is it “in the office” or “at the office”?

στο γραφείο comes from σε + το γραφείο:

σε = in / at / on (a general preposition)
το γραφείο = the office (neuter)

In speech and writing, σε + το contracts to στο.

Depending on context, στο γραφείο can be translated as:

in the office
at the office

Greek σε is broader than English “in/at/on,” so you choose the best English preposition by context. Here, “at the office” or “in the office” both sound fine.

Why don’t I see an article before γραφείο? Isn’t Greek supposed to use articles a lot?

The article is there, but it’s hidden inside the contraction:

Full form: σε το γραφείο
Contracted: στο γραφείο

So το (the neuter definite article) is present; it’s just merged into στο.
This contraction happens very regularly:

σε + το → στο
σε + τον → στον
σε + την → στη(ν)
σε + τους → στους, etc.

So you are indeed saying “in/at the office”, not just “in/at office.”

Why is σήμερα at the end of the sentence? Can it go somewhere else?

Yes, σήμερα (“today”) is quite flexible in word order. These are all possible:

Όλος ο κόσμος στο γραφείο είναι κουρασμένος σήμερα.
Σήμερα όλος ο κόσμος στο γραφείο είναι κουρασμένος.
Όλος ο κόσμος σήμερα στο γραφείο είναι κουρασμένος.

The most neutral/common is probably with σήμερα at the end or at the very beginning.

Placing σήμερα at the beginning (Σήμερα…) often gives a little extra emphasis to “today as opposed to other days”. At the end, it simply states when the situation holds, without special emphasis.

How does είναι κουρασμένος work? Is it like “has tiredness” or “is tired”?

The structure is:

είμαι + adjective → “to be + adjective”

So:

είναι κουρασμένος = “he/she/it is tired”
είμαι κουρασμένος = I am tired

Here, κουρασμένος is an adjective formed from the verb κουράζω / κουράζομαι (to tire / to get tired). It describes a state, just like English “tired.”

Compare:

Είμαι κουρασμένος. = I am tired. (state)
Κουράστηκα. = I got tired / I became tired. (event, past)
Έχω κουραστεί. = I have gotten tired / I am exhausted. (result of an action, often stronger)

In your sentence, είναι κουρασμένος is the normal way to say “is tired.”

Why is κουρασμένος written with -μένος? What are the other forms?

κουρασμένος is the masculine singular form of the adjective meaning “tired.” It has gender and number forms:

Masculine: κουρασμένος (sg), κουρασμένοι (pl)
Feminine: κουρασμένη (sg), κουρασμένες (pl)
Neuter: κουρασμένο (sg), κουρασμένα (pl)

The ending -μένος / -μένη / -μένο often comes from the perfective passive participle of a verb and is very common in adjectives derived from verbs:

κουράζω → κουρασμένος (tired)
παντρεύω → παντρεμένος (married)
αγχώνω → αγχωμένος (stressed)

In this sentence, it behaves purely as an ordinary adjective agreeing with ο κόσμος.

Can I change the word order to Σήμερα όλος ο κόσμος στο γραφείο είναι κουρασμένος or Όλος ο κόσμος στο γραφείο σήμερα είναι κουρασμένος?

Yes, those are both grammatical and natural:

Σήμερα όλος ο κόσμος στο γραφείο είναι κουρασμένος.
– Emphasis a bit more on today.
Όλος ο κόσμος στο γραφείο σήμερα είναι κουρασμένος.
– Slight extra focus on “today at the office, everyone (there) is tired”.

Greek word order is relatively flexible. The core requirement is that the forms agree:

Όλος ↔ ο κόσμος (masculine singular)
κουρασμένος ↔ ο κόσμος (masculine singular)

As long as that agreement is maintained, you can move σήμερα and some other elements for emphasis.

How is the whole sentence pronounced and where are the stresses?

The sentence is:

Όλος ο κόσμος στο γραφείο είναι κουρασμένος σήμερα.

Stressed syllables in capitals (approximate):

Ó-los
o KÓS-mos
sto gra-FÍ-o
Í-ne
kouraz-MÉ-nos
SÍ-me-ra

Rough phonetic approximation (using English-like sounds):

Ólos o KÓsmos sto gra-FEE-o Íne koura-ZMÉ-nos SÍ-mera.

In normal speech, words flow together smoothly; for example:

κόσμος στο will sound like KÓsmosto, with the ς linking to the next word.