Learn Hardcore Greek: Η φίλη μου είναι πολύ υγιής γιατί τρώει λαχανικά και κάνει άσκηση. - My friend female is very healthy because she eats vegetables and exercises.

Η φίλη μου literally is the friend my, but it simply means my friend.
The structure is:
- η = the (feminine, singular, nominative)
- φίλη = friend (female)
- μου = my

Leaving out the article (φίλη μου) is possible, but it sounds:

more emotional or poetic (e.g. in songs, letters)
or like a vocative (calling someone: φίλη μου! = my friend!).

In a neutral statement like this, η φίλη μου is the normal form.

Why is μου after the noun (φίλη μου) and not before it, like in English my friend?

In Greek, short possessive pronouns like μου, σου, του, της, μας, σας, τους usually follow the noun they modify.

η φίλη μου = my friend
το βιβλίο σου = your book
το σπίτι μας = our house

Putting μου before the noun (μου φίλη) is not normal in standard Greek. You might see it only:

in poetry or song lyrics for rhythm
or in very old-fashioned/literary styles.

So: in everyday Greek, possessives of this type come after the noun.

What’s the difference between φίλη and φίλος?

Both mean friend, but they mark the gender of the person:

η φίλη = female friend
ο φίλος = male friend

The article also changes:

ο φίλος μου = my (male) friend
η φίλη μου = my (female) friend

If you want to be gender‑neutral or you don’t care about the gender, in practice people still pick one of the two, often ο φίλος μου, unless the gender is clear from context.

Why is the verb είναι here? How does it agree with η φίλη μου?

Είναι is the 3rd person singular form of the verb είμαι (to be):

είμαι = I am
είσαι = you are (singular)
είναι = he / she / it is

The subject here is η φίλη μου (my friend), which is 3rd person singular (like she in English), so we use είναι:

Η φίλη μου είναι πολύ υγιής.
= My friend is very healthy.

What is the difference between υγιής and υγιεινός / υγιεινή / υγιεινό?

This is a very important distinction:

υγιής = healthy (as a person, an animal, a body)
- Είναι υγιής. = She is healthy.
- Έχει υγιή καρδιά. = He has a healthy heart.
υγιεινός / υγιεινή / υγιεινό = healthy / wholesome (as food, habits, lifestyle)
- υγιεινή διατροφή = healthy diet
- υγιεινό φαγητό = healthy food

So in this sentence:

Η φίλη μου είναι πολύ υγιής means My friend is very healthy (as a person).
If we said πολύ υγιεινή, it would sound like we are saying she is very healthy (food), which doesn’t make sense.

Why is the form υγιής used here and not υγιές or υγιή?

Adjectives in Greek agree with the noun in gender, number, and case.

Noun: η φίλη
- feminine, singular, nominative (subject)

The adjective υγιής has these main forms in the singular:

masculine / feminine nominative: υγιής
neuter nominative / accusative: υγιές
masculine / feminine accusative: υγιή

Since η φίλη is feminine nominative singular, the correct agreeing form is υγιής:

η φίλη μου είναι υγιής ✅
το παιδί μου είναι υγιές ✅ (neuter)
Βλέπω μια υγιή γυναίκα. ✅ (feminine accusative)

What exactly is πολύ doing here? Is it an adjective or an adverb?

In πολύ υγιής, πολύ works as an adverb, meaning very.

είναι υγιής = she is healthy
είναι πολύ υγιής = she is very healthy

Greek has two related words:

πολύ (indeclinable adverb) = very / a lot
- πολύ καλός = very good
- δουλεύει πολύ = he works a lot
πολύς / πολλή / πολύ (declinable adjective) = much / many / a lot of
- πολύς χρόνος = much time
- πολλή δουλειά = a lot of work
- πολλά λαχανικά = many vegetables

In this sentence, because it is intensifying an adjective (υγιής), πολύ is an adverb: very.

Why is γιατί used here? I thought γιατί means why, but here it looks like because. Is that right?

Yes. Γιατί in Modern Greek can mean both:

why (question)
because (answer / conjunction)

The difference comes from context and punctuation:

Question:
- Γιατί τρώει λαχανικά; = Why does she eat vegetables?
Answer / reason:
- Τρώει λαχανικά γιατί είναι υγιεινά. = She eats vegetables because they are healthy.

In your sentence, γιατί clearly introduces the reason:

Η φίλη μου είναι πολύ υγιής, γιατί τρώει λαχανικά και κάνει άσκηση.
= My friend is very healthy because she eats vegetables and exercises.

You could also use επειδή instead of γιατί here, with almost the same meaning:

… επειδή τρώει λαχανικά και κάνει άσκηση.

Why don’t we say αυτή τρώει λαχανικά και κάνει άσκηση? Where is the subject she?

Greek is a “pro‑drop” language: subject pronouns are often omitted when they are clear from the verb ending.

τρώει = he/she/it eats (3rd person singular)
κάνει = he/she/it does (3rd person singular)

We already know the subject from the previous clause:

Η φίλη μου είναι πολύ υγιής γιατί τρώει…
→ My friend is very healthy because [she] eats…

So αυτή is understood and is normally left out.
You use αυτή only if you want to emphasize she in contrast to someone else:

Αυτή τρώει λαχανικά, αλλά ο αδελφός της όχι.
= She eats vegetables, but her brother doesn’t.

Does τρώει mean eats or is eating? Which English tense is it?

Greek present tense covers both English:

simple present (she eats vegetables)
present continuous (she is eating vegetables)

So τρώει can mean:

she eats
she is eating

In this sentence, because we are describing a habit that explains why she is healthy, the natural English is:

because she eats vegetables and exercises

Greek does not need a special continuous form here; the present τρώει / κάνει already includes that idea of regular action from context.

Why is it λαχανικά without an article? When do we say τα λαχανικά?

Λαχανικά is the plural of λαχανικό (vegetable), neuter gender.

λαχανικό = vegetable
λαχανικά = vegetables

In Greek, when we talk about things in general, especially with verbs like τρώω, πίνω, καπνίζω, we often omit the article:

Τρώει λαχανικά. = She eats vegetables (in general).
Τρώω φρούτα. = I eat fruit.

If you say τα λαχανικά, it usually means the vegetables in a more specific sense:

Τρώει τα λαχανικά.
= She eats the vegetables (the ones we mentioned / the ones on the plate).

Here we are describing a general healthy habit, so τρώει λαχανικά (no article) is the natural choice.

What does κάνει άσκηση literally mean, and are there other common ways to say exercises?

Literally:

κάνει = does / makes
άσκηση = exercise

So κάνει άσκηση = does exercise.

Other very common ways to say to exercise / to work out in Greek:

κάνει γυμναστική = does gym / does physical exercise
γυμνάζεται = he/she works out, exercises (reflexive verb)

All of these are natural here:

… γιατί τρώει λαχανικά και κάνει άσκηση.
… γιατί τρώει λαχανικά και κάνει γυμναστική.
… γιατί τρώει λαχανικά και γυμνάζεται.

Άσκηση is singular here (not ασκήσεις), just like English does exercise or gets exercise, not necessarily does exercises.

Which words are the direct objects in this sentence, and which case are they in?

The verbs τρώει and κάνει both take direct objects:

τρώει λαχανικά
- Verb: τρώει (eats)
- Direct object: λαχανικά (vegetables)
κάνει άσκηση
- Verb: κάνει (does)
- Direct object: άσκηση (exercise)

In Greek, direct objects are typically in the accusative case.

So:

λαχανικά is neuter plural accusative
άσκηση is feminine singular accusative

They answer the questions:

Τρώει τι; → λαχανικά
Κάνει τι; → άσκηση