Η υγεία έχει μεγαλύτερη αξία από τα χρήματα, αυτό το ξέρω καλά.

Greek very often uses the definite article with abstract nouns and with general statements.

So Η υγεία is the natural way to say health in a general sense here. It does not mean a specific health that has already been mentioned. It is simply how Greek commonly talks about concepts like:

• η αγάπη = love
• η ζωή = life
• η ελευθερία = freedom

So Η υγεία sounds normal and idiomatic.

Greek can absolutely say something like είναι πιο σημαντική or είναι πολυτιμότερη, but έχει αξία is a very common and natural structure.

Literally, έχει αξία means has value.

So:

• Η υγεία έχει μεγαλύτερη αξία = health has greater value
• very natural Greek
• slightly formal or thoughtful in tone

It is just one normal way Greek expresses the idea of being more valuable.

Because μεγαλύτερη agrees with αξία, and αξία is feminine singular.

Here is what is happening:

• base adjective: μεγάλος = big, great
• comparative: μεγαλύτερος = bigger, greater

Then it changes form to match the noun:

• masculine: μεγαλύτερος
• feminine: μεγαλύτερη
• neuter: μεγαλύτερο

Since the noun is αξία and αξία is feminine singular, Greek uses μεγαλύτερη αξία.

It can do both.

In comparisons, από often means than:

• μεγαλύτερος από = bigger than
• καλύτερος από = better than
• πιο ακριβός από = more expensive than

So in this sentence:

• μεγαλύτερη αξία από τα χρήματα = greater value than money

This is a very common Greek comparison pattern.

Two separate things are going on here.

First, Greek often uses the article in general statements, so τα χρήματα is perfectly normal.

Second, χρήματα is very commonly plural when it means money in Modern Greek. That is just the usual everyday word.

So:

• τα χρήματα = money
• literally plural in form
• but translated as singular money in English

You may also see χρήμα, but χρήματα is the ordinary everyday choice in many contexts.

A learner might not see much case change here because some forms look the same, but the sentence still has case structure.

• Η υγεία is nominative because it is the subject.
• μεγαλύτερη αξία is accusative because it is the object of έχει.
• τα χρήματα is accusative after από in this comparison.
• αυτό is also the object in the second clause, and the clitic το refers back to it.

One tricky point: some feminine singular nouns and neuter plural nouns look the same in nominative and accusative, so the case is not always obvious from the ending alone.

Yes, and that repetition is normal in Greek.

This is a very common structure called object doubling or clitic doubling.

• αυτό is the full stressed form: that
• το is the unstressed object pronoun: it

So αυτό το ξέρω καλά is literally something like:

• that, I know it well

In natural English we usually would not repeat it, but in Greek this is very common when the speaker wants to highlight or emphasize the object.

Yes.

Το ξέρω καλά is a very natural sentence and means I know that well or I know it well, depending on context.

The longer version αυτό το ξέρω καλά is more emphatic. It draws attention to that.

So the difference is roughly:

• το ξέρω καλά = neutral
• αυτό το ξέρω καλά = emphatic, like that, I know well

Greek word order is more flexible than English word order, especially with pronouns and emphasis.

Putting αυτό first gives it focus. The speaker is stressing that particular fact.

Compare:

• το ξέρω καλά = neutral
• αυτό το ξέρω καλά = that, I know well
• καλά το ξέρω = possible, but with different emphasis

So the chosen order is mainly about emphasis, not basic meaning.

Yes, καλά is an adverb here, meaning well.

In Modern Greek, καλά is the normal everyday adverb form used in many situations:

• μιλάει καλά = he speaks well
• το ξέρω καλά = I know it well

Καλώς also exists, but it is more formal and is often used in fixed expressions, such as:

• Καλώς ήρθες = welcome

So in this sentence, καλά is the normal choice.

The comma separates the main statement from an added comment:

• Η υγεία έχει μεγαλύτερη αξία από τα χρήματα
• αυτό το ξέρω καλά

The second part works like an emphatic personal comment: that I know well.

So the comma helps show a pause and makes the sentence feel more natural and expressive. In English, you might also separate this kind of comment with a comma or a dash.

A rough pronunciation is:

ee yee-EE-a E-khee me-ga-LY-te-ree a-KSEE-a a-PO ta HREE-ma-ta, af-TO to KSE-ro ka-LA

A few useful pronunciation notes:

• υ in υγεία sounds like ee
• γ before ε or ι is a softer sound, not a hard English g
• χ in έχει is not English h; it is a Greek friction sound
• ξ in ξέρω sounds like ks
• the written accent shows which syllable is stressed

The stressed syllables are:

• υγεία
• έχει
• μεγαλύτερη
• αξία
• από
• αυτό
• ξέρω
• καλά