Learn Hardcore Greek: Νιώθω πολύ τυχερός που έχω τόσο υπομονετική δασκάλα. - I feel very lucky male that I have such a patient teacher female.

Νιώθω πολύ τυχερός = I feel very lucky (it describes your current feeling or subjective experience).
Είμαι πολύ τυχερός = I am very lucky (it sounds more like a fact about your situation).

Both are correct here; using νιώθω just emphasizes that it is your personal feeling at this moment.

Why is it τυχερός and not τυχερή? Does it change with the speaker’s gender?

Τυχερός is a masculine adjective meaning lucky.

In Greek, adjectives agree in gender with the person they describe. The subject I (εγώ) is not written, but the adjective tells us the gender:

A man would say: Νιώθω πολύ τυχερός…
A woman would say: Νιώθω πολύ τυχερή…

So yes, the adjective changes:

Masculine: τυχερός
Feminine: τυχερή
Neuter: τυχερό (for neuter nouns, not for people speaking about themselves)

Why is it πολύ τυχερός and not something like πολλός τυχερός?

Πολύ here is an adverb meaning very.

πολύ (adverb) modifies adjectives or other adverbs:
- πολύ τυχερός = very lucky
- πολύ καλός = very good
- πολύ αργά = very late

Πολλός / πολλή / πολύ (with gender and number changes) is the adjective meaning much / many, which goes before nouns:

πολλοί άνθρωποι = many people
πολλή δουλειά = a lot of work

In this sentence you want very lucky, so the invariable adverb πολύ is correct: πολύ τυχερός.

What exactly does που mean here? Is it “that” or “because” or something else?

In this sentence, που is a conjunction that introduces a subordinate clause:

Νιώθω πολύ τυχερός που έχω…
= I feel very lucky that I have…

It is close in meaning to ότι (“that”), but:

που is more informal and very common in spoken Greek.
It often has a slightly emotional or personal tone.

You could also say:

Νιώθω πολύ τυχερός επειδή έχω τόσο υπομονετική δασκάλα.
(I feel very lucky because I have such a patient teacher.)

Επειδή = “because” (gives a reason more explicitly).
Που here is more like “(that) I have…”, linking your feeling to the fact.

What does τόσο add to the meaning? How is it different from just υπομονετική δασκάλα?

Τόσο expresses degree: so / so much / such.

υπομονετική δασκάλα = a patient teacher
τόσο υπομονετική δασκάλα = such a patient teacher / so patient a teacher

So τόσο intensifies the adjective:

τόσο υπομονετική = so patient

It makes the compliment stronger, emphasizing how patient she is.

Why is it τόσο υπομονετική and not something like τόση υπομονετική?

Greek has two different but related forms:

τόσο as an adverb of degree (invariable):
- τόσο καλός, τόσο καλή, τόσο καλό = so good
- τόσο υπομονετική δασκάλα = so patient a teacher
  Here, τόσο does not change for gender or number.
τόσος / τόση / τόσο as an adjective/pronoun (“so much / so many”):
- τόση υπομονή = so much patience
- τόσοι μαθητές = so many students

In the sentence you’re modifying an adjective (υπομονετική) for degree (so patient), so you use the adverb form: τόσο υπομονετική.

Why is there no word for “a” before δασκάλα? Why not μια δασκάλα?

Greek often omits the indefinite article (ένας / μία / ένα) where English uses a / an, especially with professions and roles.

Έχω δασκάλα. = I have a (female) teacher.
Είναι δασκάλα. = She is a teacher.

In your sentence:

τόσο υπομονετική δασκάλα naturally means such a patient teacher or such a very patient teacher.

You can add the article:

Νιώθω πολύ τυχερός που έχω μια τόσο υπομονετική δασκάλα.

That’s also correct and maybe even a bit more explicit, but native speakers very often drop μια here.

What case is υπομονετική δασκάλα, and why that case?

Δασκάλα (teacher, fem.) is:

Nominative singular: η δασκάλα
Accusative singular: τη δασκάλα

The forms are identical in spelling; only the article changes.

In the sentence:

έχω (I have) + δασκάλα (teacher)
→ δασκάλα is the direct object of έχω, so it is in the accusative case.

The adjective υπομονετική agrees with δασκάλα in gender, number, and case:

Feminine, singular, accusative → υπομονετική δασκάλα

Because nominative and accusative singular feminine look the same here, you only know it’s accusative from the grammar of the sentence.

What is the gender difference between δασκάλα and δάσκαλος?

δασκάλα = female teacher (feminine noun)
δάσκαλος = male teacher (masculine noun)

Some examples:

μια υπομονετική δασκάλα = a patient (female) teacher
ένας υπομονετικός δάσκαλος = a patient (male) teacher

The adjective changes depending on the noun:

υπομονετική δασκάλα (fem.)
υπομονετικός δάσκαλος (masc.)

Could I say Αισθάνομαι πολύ τυχερός instead of Νιώθω πολύ τυχερός?

Yes. Αισθάνομαι also means I feel.

Νιώθω πολύ τυχερός
Αισθάνομαι πολύ τυχερός

Both are correct and natural.
Νιώθω is more common in everyday speech and a bit simpler; αισθάνομαι can sound slightly more formal or “standard”, but the difference is small in this context.

Is the word order τόσο υπομονετική δασκάλα fixed, or can I change it?

The chosen word order is the most natural here, but Greek is flexible.

Most natural:

τόσο υπομονετική δασκάλα = so patient a teacher

Other possibilities:

μια τόσο υπομονετική δασκάλα (adding the article)
δασκάλα τόσο υπομονετική – possible, but more marked and emphasizes the adjective even more, a bit like saying “a teacher so patient”.

The pattern τόσο + adjective + noun is very common and sounds completely natural.

How would a woman say the whole sentence?

Only the adjective referring to the speaker’s gender changes:

Masculine speaker:
- Νιώθω πολύ τυχερός που έχω τόσο υπομονετική δασκάλα.
Feminine speaker:
- Νιώθω πολύ τυχερή που έχω τόσο υπομονετική δασκάλα.

Everything else stays the same.