Ο καινούριος συνεργάτης φαίνεται πολύ ήρεμος και ευγενικός.

A word-by-word breakdown:

• Ο = the
• καινούριος = new
• συνεργάτης = colleague / associate / coworker / partner, depending on context
• φαίνεται = seems / appears
• πολύ = very
• ήρεμος = calm
• και = and
• ευγενικός = polite / kind / courteous

So the structure is basically:

The new colleague seems very calm and polite.

Ο is the masculine singular nominative form of the definite article, meaning the.

It matches συνεργάτης, which is a masculine singular noun and is the subject of the sentence.

Greek articles change depending on:

• gender
• number
• case

Here:

• ο = masculine
• singular
• nominative

So ο συνεργάτης = the colleague.

Because adjectives in Greek must agree with the noun they describe in:

• gender
• number
• case

The noun συνεργάτης is:

• masculine
• singular
• nominative

So the adjective also has to be masculine singular nominative:

• καινούριος συνεργάτης = new colleague

If the noun were feminine, you would use a different form, such as καινούρια.
If it were plural, the form would change again.

Many masculine nouns do end in -ος, but not all of them. Greek has several common masculine noun patterns, including nouns ending in:

• -ος
• -ης
• -ας

So συνεργάτης is simply a normal masculine noun of the -ης type.

That means:

• it is still masculine
• it still takes ο in the nominative singular
• adjectives describing it still use masculine forms

So even though it ends in -ης, it behaves like a masculine noun.

They are close, but not always identical.

• καινούριος often means new in the sense of brand-new / recent / newly arrived
• νέος can mean new, but it can also mean young

In many everyday sentences, either could work, but καινούριος συνεργάτης strongly suggests the newly arrived / new colleague.

If you said νέος συνεργάτης, it could also work, but depending on context it might sound a little more ambiguous.

Because φαίνεται means seems / appears, not is.

So the sentence does not directly say that the colleague is calm and polite as a fact. It says that he seems or appears calm and polite.

That adds a nuance of impression or observation.

Compare:

• Ο συνεργάτης είναι ήρεμος και ευγενικός.
  = The colleague is calm and polite.

• Ο συνεργάτης φαίνεται ήρεμος και ευγενικός.
  = The colleague seems calm and polite.

It looks passive, and historically it is related to middle/passive forms, but in modern Greek φαίνομαι is a normal verb meaning to seem / to appear.

Its present tense goes like this:

• φαίνομαι = I seem / appear
• φαίνεσαι = you seem
• φαίνεται = he/she/it seems

So φαίνεται is simply the 3rd person singular form needed for ο συνεργάτης.

You do not need to translate it as a passive here. Just think of it as the standard form of the verb φαίνομαι.

Because they describe the subject ο καινούριος συνεργάτης.

These are called predicate adjectives: they come after a linking-type verb such as είναι or φαίνεται, and they still agree with the subject.

Since συνεργάτης is masculine singular, we get:

• ήρεμος
• ευγενικός

If the subject were feminine, you would expect:

• ήρεμη
• ευγενική

So Greek keeps adjective agreement even after verbs like seems.

Here πολύ means very.

It modifies the adjective ήρεμος:

• πολύ ήρεμος = very calm

In Greek, πολύ can mean different things depending on how it is used:

• as an adverb: very
• as an adjective/pronoun: much / many / a lot

In this sentence it is clearly an adverb, so very is the natural translation.

Grammatically, it directly sits before ήρεμος, so its most direct connection is with that adjective.

However, in natural interpretation, many speakers may understand the whole phrase as meaning the person seems very calm and polite, with πολύ giving extra emphasis at least to the first adjective and sometimes loosely to the overall description.

If someone wanted to make it absolutely clear that both adjectives are equally intensified, they might say something like:

• φαίνεται πολύ ήρεμος και πολύ ευγενικός

But the original sentence sounds perfectly natural.

Here και simply means and, linking the two adjectives:

• ήρεμος και ευγενικός = calm and polite

Very often και does mean and, but depending on context it can also have other uses, such as also / even.

In this sentence, though, it is the basic coordinating and.

Yes. Greek word order is more flexible than English because case endings and agreement give extra grammatical information.

The neutral, straightforward order here is:

Ο καινούριος συνεργάτης φαίνεται πολύ ήρεμος και ευγενικός.

But Greek can move elements around for emphasis. For example, a speaker might front an adjective or adverb in some contexts.

Still, for a learner, the given order is the most natural standard pattern:

• article + adjective + noun
• verb
• adverb + adjectives

So it is a very good model sentence.

Yes. συνεργάτης can mean several related things depending on context, such as:

• colleague
• coworker
• associate
• collaborator
• business partner

In everyday workplace contexts, colleague or coworker is often the best fit.
In business or professional contexts, associate or partner may sometimes fit better.

So the exact English word depends on the situation.

A rough pronunciation guide is:

o ke-noo-ree-os sy-ner-GA-tis FE-ne-te po-LI I-re-mos ke ev-ye-ni-KOS

A few helpful points:

• καινούριος has stress on -νού-
• συνεργάτης has stress on -γά-
• φαίνεται has stress on the first syllable: ΦΑΙ-
• πολύ has stress on the last syllable
• ήρεμος begins with a vowel sound
• ευγενικός is stressed on the last syllable

Also:

• αι is pronounced like e
• ευ is often pronounced ev before voiced sounds

Greek usually does not need subject pronouns when the verb ending already shows the person and number.

Here the subject is explicitly stated as Ο καινούριος συνεργάτης, so there is no need for a separate pronoun like he.

In fact, Greek often omits subject pronouns unless there is special emphasis or contrast.

You would need to change the article and all the adjectives so they agree with a feminine subject.

For example:

Η καινούρια συνεργάτιδα φαίνεται πολύ ήρεμη και ευγενική.

Changes:

• Ο → Η
• καινούριος → καινούρια
• συνεργάτης → συνεργάτιδα
• ήρεμος → ήρεμη
• ευγενικός → ευγενική

The verb φαίνεται stays the same because it is still 3rd person singular.

It is in the nominative case because it is the subject of the sentence.

You can tell from:

• the article ο
• the sentence role: the colleague is the one who seems
• the adjective agreement: καινούριος matches a masculine singular nominative noun

So the core subject phrase is:

• ο καινούριος συνεργάτης

That is a nominative noun phrase meaning the new colleague.