Learn Hardcore Greek: Η υγεία είναι πολύ σημαντική για το σώμα και το κεφάλι. - Health is very important for the body and the head.

η υγεία = health
- η is the feminine singular definite article (like the).
- The ending -ία in υγεία is very often feminine (e.g. η ιστορία, η δημοκρατία).

You generally have to learn the gender with each noun, but endings like -α, -η, -ία are good clues that the noun is probably feminine.

Why is the adjective σημαντική and not σημαντικός or σημαντικό?

Adjectives in Greek agree with the noun in:

gender (masculine / feminine / neuter)
number (singular / plural)
case (nominative, accusative, etc.)

Here the pattern is:

η υγεία (feminine, singular, nominative)
So the adjective must also be feminine, singular, nominative → σημαντική.

For this adjective:

Masculine: σημαντικός (ο σημαντικός φίλος)
Feminine: σημαντική (η σημαντική μέρα)
Neuter: σημαντικό (το σημαντικό θέμα)

Since υγεία is feminine, we use σημαντική.

What exactly does πολύ mean here? Is it “very” or “much”?

In this sentence, πολύ functions as an adverb meaning very:

πολύ σημαντική = very important

Some points:

Before adjectives and adverbs, πολύ = very
- πολύ καλός = very good
- τρέχει πολύ = he/she runs a lot / very fast
Before verbs or with uncountable nouns, πολύ can mean much / a lot
- δουλεύω πολύ = I work a lot
- έχω πολύ χρόνο = I have a lot of time

You might also hear πάρα πολύ (= very, very / extremely):
Η υγεία είναι πάρα πολύ σημαντική.

Why doesn’t πολύ change form to agree with σημαντική? Shouldn’t it be πολλή?

Both forms exist, but they have different roles:

πολύ (in this sentence) is an adverb modifying the adjective σημαντική → adverbs in Greek do not change for gender/number/case, so it stays πολύ.
πολλή is the feminine adjective form of πολύς (much/many):
- πολλή δουλειά = much work
- πολλοί άνθρωποι = many people (masc. pl.)
- πολλά παιδιά = many children (neut. pl.)

So:

πολύ σημαντική = very important
πολλή σημασία = much importance

Why do we use για with το σώμα και το κεφάλι? Could we use στο instead?

για literally means for and often expresses purpose, benefit, or relevance:

σημαντική για το σώμα = important for the body

If you said:

σημαντική στο σώμα → in/at the body, which sounds strange in this context and is not how you express “important for the body”.

So:

για
- accusative = for (benefit, relation):
  - κακό για την υγεία = bad for the health
  - χρήσιμο για τα παιδιά = useful for children

Why do we say το σώμα και το κεφάλι with the article το twice? Could we say το σώμα και κεφάλι or σώμα και κεφάλι?

The most natural forms are:

το σώμα και το κεφάλι (article repeated)
or, a bit more compact: το σώμα και το κεφάλι μας (our body and head)

About dropping the article:

το σώμα και κεφάλι sounds incomplete or awkward.
σώμα και κεφάλι (no articles) is possible in some very general, title-like, or poetic contexts, but in normal speech and writing, Greeks generally use the definite article with body parts in this kind of sentence.

So for everyday, natural Greek, keep το before both nouns:
για το σώμα και το κεφάλι.

What genders are σώμα and κεφάλι, and how can I tell?

Both are neuter nouns:

το σώμα = the body
το κεφάλι = the head

Clues:

The article το is neuter singular.
Many neuter nouns end in -μα or -ι:
- το σώμα, το πνεύμα, το γράμμα
- το παιδί, το σπίτι, το κεφάλι

As with all nouns, you learn their gender together with the noun, but these endings are strong hints.

Does το κεφάλι mean “head” physically, or can it also mean “mind”?

Primarily:

το κεφάλι = the head (the physical part of the body).

In some contexts, it can extend metaphorically to ideas like:

χτυπάω το κεφάλι μου = I hit my head
μου έφαγε το κεφάλι (idiomatic) = he/she gave me a very hard time

For mind/brain in a more abstract sense, Greek usually uses:

το μυαλό = mind/brain (in the sense of thinking)
- είναι καλό για το μυαλό = it is good for the mind

In your sentence, it is most naturally understood as the physical head (though in casual speech people may loosely understand it as head/brain).

Could I change the word order to Η υγεία για το σώμα και το κεφάλι είναι πολύ σημαντική?

Yes, that word order is grammatically correct and understandable.

However, the original:

Η υγεία είναι πολύ σημαντική για το σώμα και το κεφάλι.

sounds more neutral and natural. Greek allows quite a bit of flexibility in word order, but:

Subject – Verb – Complement (Η υγεία είναι πολύ σημαντική …)
is the most common pattern, especially in simple statements like this.

Why is there no word for “it” in the Greek sentence (like “It is very important…”)?

Greek is a pro-drop language: subject pronouns (I, you, he, she, it, we, they) are often omitted when they are clear from the verb form or context.

In this sentence:

The subject is explicitly η υγεία.
English: Health is very important… (no “it” here either)
If the subject were only implied, Greek could still omit “it”:
- Είναι σημαντικό. = It is important.

So Greek simply doesn’t need a separate word for it when the subject is clear.

How is Η υγεία pronounced, given the spelling with η and υ?

Pronunciation (modern Greek):

Η υγεία → roughly: ee yeh-AH (3 syllables: υ-γε-ία)

Details:

Η (capital eta) is pronounced /i/, like ee in see.
υγ here is pronounced like γ before a front vowel: a soft y sound starting the syllable → γι = yee.
υγεία → yi-ˈʝi.a, often heard as yee-YEE-a or yi-YEH-a, depending on speed/accent.

So the whole phrase:

Η υγεία → ee yi-YEE-a (simplified).

How do you pronounce the αι in κεφάλι, and what sound does it represent?

In modern Greek, the vowel combination αι is pronounced /e/, like:

e in bed

So:

κεφάλι ≈ ke-FA-lee (stress on -φα-)

Syllables:

κε – φα – λι → ke-FA-lee

Spelling:

αι is a digraph that historically was a diphthong, but in modern Greek it is just the simple e sound.