Δείχνεις πολύ κουρασμένος σήμερα.

Here, Δείχνεις means you look or you seem.

The basic verb is δείχνω, which often means to show, but in everyday Greek it can also mean to look / appear in sentences like this:

• Δείχνεις κουρασμένος. = You look tired.
• Δείχνει χαρούμενος. = He looks happy.

So in this sentence, it does not mean you show, but rather you give the impression of being.

Because it is the 2nd person singular form of the verb in the present tense.

The verb is δείχνω = I show / I look / I appear.
Its present-tense forms include:

• δείχνω = I look / show
• δείχνεις = you look / show
• δείχνει = he/she/it looks / shows
• δείχνουμε = we look / show
• δείχνετε = you (plural/formal) look / show
• δείχνουν = they look / show

So Δείχνεις specifically tells you the subject is you.

It is understood from the verb ending.

Greek often leaves out subject pronouns when they are clear from the verb form. So:

• Δείχνεις πολύ κουρασμένος σήμερα.

already means:

• You look very tired today.

You could add εσύ for emphasis:

• Εσύ δείχνεις πολύ κουρασμένος σήμερα.

But that usually sounds emphatic, like you in particular.

Because κουρασμένος agrees with the person being described.

It is a masculine singular form, so this sentence is addressed to one male person.

Forms:

• κουρασμένος = masculine singular
• κουρασμένη = feminine singular
• κουρασμένο = neuter singular
• κουρασμένοι / κουρασμένες / κουρασμένα = plural forms, depending on gender

So:

• to a man: Δείχνεις πολύ κουρασμένος σήμερα.
• to a woman: Δείχνεις πολύ κουρασμένη σήμερα.

It is used here as an adjective, meaning tired.

Historically, it comes from a participle related to the verb κουράζω = to tire, but for learners it is best to treat κουρασμένος / κουρασμένη / κουρασμένο as a normal adjective meaning tired.

In this sentence, it works like a predicate adjective after Δείχνεις:

• Δείχνεις κουρασμένος. = You look tired.

Because Greek does not need a verb like to be in this structure.

In English, we say:

• You look tired.

not

• You look are tired.

Greek works the same way here:

• Δείχνεις κουρασμένος.

The adjective κουρασμένος goes directly after the verb Δείχνεις, just like tired after look in English.

Πολύ means very here.

So:

• κουρασμένος = tired
• πολύ κουρασμένος = very tired

It is placed before the adjective, just like in English:

• very tired
• πολύ κουρασμένος

Σήμερα means today.

Yes, it can move. Greek word order is fairly flexible, especially with time words like this.

All of these are possible:

• Δείχνεις πολύ κουρασμένος σήμερα.
• Σήμερα δείχνεις πολύ κουρασμένος.
• Δείχνεις σήμερα πολύ κουρασμένος.

The original version is very natural. Putting σήμερα at the end is common and neutral.

Not completely. Greek word order is more flexible than English.

The basic sentence:

• Δείχνεις πολύ κουρασμένος σήμερα.

is neutral and natural. But Greek can move elements for emphasis or style:

• Σήμερα δείχνεις πολύ κουρασμένος. = emphasis on today
• Πολύ κουρασμένος δείχνεις σήμερα. = stronger emphasis on very tired

Even though the order can change, the agreement and endings still tell you how the words fit together.

Yes. Φαίνεσαι πολύ κουρασμένος σήμερα is also natural and common.

Both can mean you look / you seem very tired today, but there is a slight nuance:

• φαίνομαι often means seem / appear
• δείχνω often means look / give the impression

In many everyday situations, the difference is small, and both are idiomatic.

You would change the adjective to the feminine form:

• Δείχνεις πολύ κουρασμένη σήμερα.

The verb Δείχνεις stays the same, because it still means you singular. Only the adjective changes to match the gender of the person being described.

You need the plural verb and a plural adjective.

For a group:

• Δείχνετε πολύ κουρασμένοι σήμερα. = to a group of men or a mixed group
• Δείχνετε πολύ κουρασμένες σήμερα. = to a group of women

If δείχνετε is formal singular you, then the adjective stays singular and matches the person’s gender:

• Δείχνετε πολύ κουρασμένος σήμερα. = formal, to one man
• Δείχνετε πολύ κουρασμένη σήμερα. = formal, to one woman

A simple pronunciation guide is:

THEE-hnees po-LEE koo-raz-ME-nos SEE-me-ra

A more careful approximation:

• Δείχνεις ≈ THEE-hnees
• πολύ ≈ po-LEE
• κουρασμένος ≈ koo-raz-ME-nos
• σήμερα ≈ SEE-me-ra

Stress falls on:

• ΔΕΙ-χνεις
• πο-ΛΥ
• κου-ρα-σμέ-ΝΟΣ
• ΣΗ-με-ρα

It is completely natural, everyday Greek.

A Greek speaker could say this if someone looks worn out, sleepy, or low-energy. It is a normal, idiomatic way to comment on someone’s appearance.

Depending on tone, it can sound:

• caring: You look very tired today
• observant: You seem very tired today
• slightly concerned: You look really tired today

So yes, this is real, natural Greek.