Learn Hardcore Greek: Είμαι ευγνώμων για την υπομονή της δασκάλας και εκτιμώ το πάθος της για τη γλώσσα. - I am grateful for the teacher’s patience and I appreciate her passion for the language.

Είμαι means I am (1st person singular), so the subject “I” is understood.
You only add Εγώ for emphasis or contrast:
- Εγώ είμαι ευγνώμων, όχι εκείνος.
  I am grateful, not him.

So Είμαι ευγνώμων... already means I am grateful... without needing Εγώ.

What exactly is ευγνώμων? Does it change for male/female?

Ευγνώμων is an adjective meaning grateful / thankful. Here it’s a predicate adjective after είμαι (I am).

The subject is “I”, so the adjective is in the nominative singular.
In modern usage, ευγνώμων is typically the same for a man or a woman:
- (άνδρας) Είμαι ευγνώμων.
- (γυναίκα) Είμαι ευγνώμων.

Traditional full forms are:

masc. ευγνώμων
fem. ευγνώμων
neut. ευγνώμον

In practice, you will almost always just see Είμαι ευγνώμων for any speaker.

Why do we say είμαι ευγνώμων για την υπομονή? Is για always used with being grateful?

The preposition για often corresponds to English “for / about / regarding”.

With being grateful, Greek commonly uses:

είμαι ευγνώμων για κάτι = I am grateful for something.

So:

Είμαι ευγνώμων για την υπομονή της δασκάλας.
I am grateful for the teacher’s patience.

Yes, για + accusative is the usual pattern in this meaning. Other verbs of emotion also often use για:

χαίρομαι για τα νέα – I’m happy about the news.
ανησυχώ για σένα – I worry about you.

What is the difference between την υπομονή and τη γλώσσα? Why is it την in one place and τη in the other?

Την and τη are actually the same article: the feminine singular accusative form of “the”.

την υπομονή – “the patience”
τη γλώσσα – “the language”

The only difference is the final -ν:

In modern spelling:

The ν is kept before:
- vowels: α, ε, η, ι, ο, υ, ω
- and often before the consonants κ, π, τ, ξ, ψ and certain clusters (μπ, ντ, γκ, κτ, etc.)
It is often dropped before other consonants in everyday writing.

So:

για την υπομονή → next word starts with a vowel (υ), so we keep ν.
για τη γλώσσα → next word starts with a γλ cluster, where dropping the ν is very common, so τη.

Grammatically they are identical; this is just a spelling/phonetic convention.

What does της δασκάλας mean grammatically? Why do we use this form, not η δασκάλα?

Της δασκάλας is in the genitive singular, meaning “of the teacher”.

η δασκάλα – the teacher (nominative, subject form)
της δασκάλας – of the teacher (genitive, showing possession)

In the sentence:

την υπομονή της δασκάλας = the patience of the teacher / the teacher’s patience.

Greek typically expresses possession with:

article + noun (owned) + article + noun (owner, in genitive)

So:

το βιβλίο του μαθητή – the student’s book
η υπομονή της δασκάλας – the teacher’s patience

Why does δασκάλας end in -ας here? I thought “teacher” (female) is η δασκάλα.

You’re right: the basic form is:

η δασκάλα – the (female) teacher (nominative)

When you put δασκάλα into the genitive singular to show possession, the ending -α changes to -ας:

της δασκάλας – of the teacher / the teacher’s

Pattern for many feminine nouns in -α:

η πόρτα → της πόρτας (door → of the door)
η μητέρα → της μητέρας (mother → of the mother)
η δασκάλα → της δασκάλας (teacher → of the teacher)

So δασκάλας is just the genitive form of δασκάλα.

What exactly does εκτιμώ mean here? Is it the same as εκτιμάω?

Εκτιμώ comes from the verb εκτιμάω/εκτιμώ and has two main meanings:

to appreciate / value / respect
- Εκτιμώ το πάθος της. – I appreciate her passion.
- Σε εκτιμώ πολύ. – I value you a lot.
to estimate
- Εκτιμώ ότι θα φτάσουμε στις 5. – I estimate we’ll arrive at 5.

In this sentence it’s clearly meaning “I appreciate / I value”.

About forms:

εκτιμάω and εκτιμώ are the same verb.
εκτιμώ is the shorter, more common form in the 1st person singular.

Conjugation (present):

εγώ εκτιμώ
εσύ εκτιμάς
αυτός/αυτή/αυτό εκτιμά
εμείς εκτιμούμε / εκτιμάμε
εσείς εκτιμάτε
αυτοί εκτιμούν(ε)

Why do we say εκτιμώ το πάθος της instead of repeating της δασκάλας?

Greek, like English, often avoids repeating the same noun if it is clear from context.

You could say:

Εκτιμώ το πάθος της δασκάλας για τη γλώσσα.
I appreciate the teacher’s passion for the language.

But since the teacher has just been mentioned, it’s very natural to replace της δασκάλας with the possessive pronoun της:

Εκτιμώ το πάθος της για τη γλώσσα.
I appreciate her passion for the language.

This sounds smoother and less repetitive, just like in English:

I am grateful for the teacher’s patience, and I appreciate *her passion for the language.*

The word της appears twice: της δασκάλας and το πάθος της. Are these the same word and how do we know what they mean?

Yes, it’s the same form της, but it plays two slightly different roles:

της δασκάλας
- της = the (feminine genitive singular article)
- δασκάλας = teacher (genitive)
  → together: της δασκάλας = of the teacher / the teacher’s.
το πάθος της
- το = the (neuter accusative singular article)
- πάθος = passion
- της = her (3rd person feminine possessive pronoun, genitive)
  → το πάθος της = her passion.

We know which is which from:

Position and structure:
- article + noun = likely article use (της δασκάλας).
- noun + της = likely possessive pronoun (her), as in το πάθος της.

How does της change if the teacher is male or if I want to say “his passion” instead of “her passion”?

For a male teacher, the noun and the possessives change:

ο δάσκαλος – the (male) teacher
του δασκάλου – of the (male) teacher

So the full masculine version would be:

Είμαι ευγνώμων για την υπομονή του δασκάλου και εκτιμώ το πάθος του για τη γλώσσα.
I am grateful for the male teacher’s patience, and I appreciate his passion for the language.

Key possessive pronouns (genitive singular):

του – his / its (masc. or neuter owner)
της – her / its (feminine owner)

Examples:

το βιβλίο του – his book
το βιβλίο της – her book

What is πάθος grammatically, and why is the article το?

Πάθος is a neuter noun.

Neuter nouns in -ος take the neuter article το in both nominative and accusative singular:

το πάθος – the passion (subject or object)
βλέπω το πάθος – I see the passion.

In the sentence:

εκτιμώ το πάθος της
- εκτιμώ – I appreciate
- το πάθος – the passion (direct object)
- της – her

So το is simply the correct neuter article for πάθος.

Can I change the word order, for example putting “teacher” earlier or later, without changing the meaning?

Yes, Greek word order is relatively flexible, though the given sentence is very natural:

Είμαι ευγνώμων για την υπομονή της δασκάλας και εκτιμώ το πάθος της για τη γλώσσα.

Some acceptable variations (with the same basic meaning), for example:

Είμαι ευγνώμων για την υπομονή της δασκάλας και για το πάθος της για τη γλώσσα, που εκτιμώ πολύ.
(I am grateful for the teacher’s patience and for her passion for the language, which I greatly appreciate.)
Είμαι ευγνώμων για την υπομονή που δείχνει η δασκάλα και εκτιμώ το πάθος της για τη γλώσσα.

However, you cannot just move things randomly without adjusting grammar. For example:

× Είμαι ευγνώμων για την υπομονή και εκτιμώ το πάθος της δασκάλας για τη γλώσσα. This is grammatically okay but now “της δασκάλας” sounds like it belongs only to πάθος (the teacher’s passion) and not clearly to υπομονή (the patience). The nuance shifts slightly.

The original sentence keeps things clear and smooth, which is why it is a good model to follow.