Learn Hardcore Greek: Ο γιατρός μου λέει ότι το στομάχι μου είναι καλά, απλώς η μέρα ήταν βαριά και αγχώθηκα. - My doctor tells me that my stomach is fine, it’s just that the day was heavy and I got stressed.

After a noun → usually possession
- ο γιατρός μου = my doctor
- το σπίτι μου = my house
- η φίλη μου = my (female) friend
With the verb (clitic before or after it) → usually indirect object ("to me")
- μου λέει = he/she tells me
- θα μου δώσει = he/she will give me

Here the most natural grouping is [Ο γιατρός μου] [λέει] = My doctor says.
If you wanted to clearly say The doctor says to me, you’d normally emphasize it differently, for example:

Ο γιατρός μού λέει ότι… (with spoken stress on μού)
or
Ο γιατρός λέει σε μένα ότι…

So in normal reading, Ο γιατρός μου is understood as my doctor.

Why is λέει (present tense) used instead of a past tense like είπε? In English I’d probably say “The doctor told me”.

Λέει is present tense (he/she says / is saying). Greek often uses the present here for:

General / repeated statements
- Ο γιατρός μου λέει ότι το στομάχι μου είναι καλά
  → My doctor (generally) tells me that my stomach is fine.
“Reporting” what someone says, close to the moment of speaking
Similar to English:
- He says my stomach is fine.

If you say:

Ο γιατρός μου είπε ότι το στομάχι μου είναι καλά.
→ My doctor told me that my stomach was/is fine.

that sounds like a specific past event: on some earlier occasion he told me.

So λέει here gives a feeling of current, still-valid information or something the doctor typically tells you, not just a one‑off past event.

What is the difference between ότι and πως here? Can I say λέει πως το στομάχι μου είναι καλά instead?

Yes, you can say Ο γιατρός μου λέει πως το στομάχι μου είναι καλά. In modern Greek:

ότι and πως both often mean that (introducing a clause):
- λέει ότι… = he says that…
- λέει πως… = he says that…

Some nuances:

ότι is a bit more neutral / standard, common in both speech and writing.
πως often feels a bit more colloquial/narrative, very common in everyday speech.

There are also cases where ότι is clearly needed as “that” (and not πως) to avoid confusion with πώς (how), but in your sentence both are fine:

Ο γιατρός μου λέει ότι το στομάχι μου είναι καλά…
Ο γιατρός μου λέει πως το στομάχι μου είναι καλά…

Both mean the same here.

Why is it το στομάχι μου είναι καλά and not είναι καλό? Isn’t στομάχι neuter, so shouldn’t the adjective be καλό?

Grammatically, το στομάχι is neuter singular, so you could match it with καλό:

το στομάχι μου είναι καλό

However, in this context καλά is not really functioning as a regular adjective agreeing with στομάχι. It is used more adverbially / as a set expression meaning fine / OK / in good condition, like English “is fine”.

Compare:

Είμαι καλά. = I am fine / I feel well.
Είναι καλά. = He/She/It is fine.
Το στομάχι μου είναι καλά. = My stomach is fine / OK.

So:

καλό → literally good as a quality: a good stomach (strange as a natural phrase).
καλά → well / OK / fine (state/condition).

Native speakers overwhelmingly say:

Το στομάχι μου είναι καλά.
rather than Το στομάχι μου είναι καλό in this medical/feeling context.

What exactly does απλώς mean here, and where can it go in the sentence? Is it like “just / simply”?

Απλώς means simply / just / merely and softens what follows:

…είναι καλά, απλώς η μέρα ήταν βαριά…
→ …is fine, it’s just that the day was heavy…

Function:

It contrasts: “There’s nothing wrong with the stomach; the real issue is only that the day was heavy.”

Position:

At the start of the second clause (as in the sentence):
- …είναι καλά, απλώς η μέρα ήταν βαριά…
After the subject:
- …είναι καλά, η μέρα απλώς ήταν βαριά… (less common but possible)
Before the verb:
- …είναι καλά, η μέρα ήταν απλώς βαριά…

All are grammatical; the given position is the most natural here.

It’s similar in feeling to English:

“…is fine; it’s just that the day was heavy and I got stressed.”

What does η μέρα ήταν βαριά really mean? Literally it’s “the day was heavy” – is this idiomatic?

Yes, it is idiomatic.

η μέρα = the day (feminine)
βαριά (feminine singular) = literally heavy, but here it means:
- hard, difficult, tiring, emotionally or physically heavy

So:

Η μέρα ήταν βαριά.
→ The day was heavy / hard / tough / exhausting.

Similar expressions:

Ήταν μια πολύ δύσκολη μέρα. = It was a very difficult day.
Πέρασα μια βαριά μέρα στη δουλειά. = I had a really heavy day at work.

Also note the agreement:

η μέρα (feminine singular)
→ βαριά (feminine singular adjective)

What tense and form is αγχώθηκα? How is it related to αγχώνω and αγχώνομαι?

Αγχώθηκα is:

person: 1st person singular
tense/aspect: aorist (simple past)
voice: mediopassive (formally the passive form, but often “reflexive” in meaning)

It comes from the verb:

αγχώνω = to stress (someone), to cause anxiety
αγχώνομαι = to be/get stressed, to feel anxiety (mediopassive)

Forms:

αγχώνομαι = I am (getting) stressed (present)
αγχωνόμουν = I was getting stressed / used to get stressed (imperfect)
αγχώθηκα = I got stressed (aorist / simple past)

In your sentence:

…και αγχώθηκα.
→ …and I got stressed / I became anxious.

So αγχώθηκα describes a completed event in the past: at some point during that heavy day, I ended up stressed.

Why is there no εγώ before αγχώθηκα? How do we know it means “I got stressed”?

Greek is a “pro-drop” language: subject pronouns are often omitted because the verb ending itself tells you the person.

αγχώθηκα ends in -κα, which is a clear marker of 1st person singular aorist.
So by itself it means I got stressed.

You can add εγώ for emphasis:

…και εγώ αγχώθηκα.
→ …and I got stressed (emphasizing that I, as opposed to others, got stressed).

But in neutral statements, Greek normally leaves the subject pronoun out:

πήγα, είδα, έφαγα, αγχώθηκα
→ I went, I saw, I ate, I got stressed.

Why is there a comma before απλώς: είναι καλά, απλώς η μέρα ήταν βαριά…? Would English also use a comma here?

The comma marks a break between two related clauses:

…το στομάχι μου είναι καλά,
→ my stomach is fine,
απλώς η μέρα ήταν βαριά και αγχώθηκα.
→ it’s just that the day was heavy and I got stressed.

The writer is making a contrast:

Problem not in the stomach,
but simply in how the day went.

In English you would normally also use a comma or a pause:

“My doctor tells me that my stomach is fine, it’s just that the day was heavy and I got stressed.”

You could also make it two sentences in both languages, but the comma + απλώς style is very natural Greek.

Could I also say Ο γιατρός μου λέει ότι είναι καλά το στομάχι μου? Is that still correct?

Yes, this is grammatically correct:

Ο γιατρός μου λέει ότι είναι καλά το στομάχι μου.

Greek word order is relatively flexible. Both:

λέει ότι το στομάχι μου είναι καλά
λέει ότι είναι καλά το στομάχι μου

are possible.

Nuance:

ότι το στομάχι μου είναι καλά feels more neutral and common.
ότι είναι καλά το στομάχι μου slightly emphasizes είναι καλά first, then clarifies what is fine (my stomach).

In everyday speech, the original order (ότι το στομάχι μου είναι καλά) is more usual here.

Why do we use definite articles ο, το, η here: Ο γιατρός, το στομάχι μου, η μέρα? In English we say “my doctor / my stomach / the day” without always repeating the.

Modern Greek uses the definite article much more than English. In your sentence:

Ο γιατρός μου = my doctor
(literally the doctor my)
το στομάχι μου = my stomach
(literally the stomach my)
η μέρα = the day

General rules:

With possessives (μου, σου, του…), you normally also use the article:
- το σπίτι μου = my house
- η μητέρα σου = your mother
- ο φίλος του = his friend
With specific things already known in context you also use the article:
- η μέρα in this context = the particular day we are talking about.

So Greek prefers article + noun + possessive where English just uses my/your/his/her etc.

How is αγχώθηκα pronounced, especially the γχ? It looks tricky.

Αγχώθηκα is pronounced approximately:

[aŋˈxɔθika]

Breakdown:

αγ-: the γ before χ turns into a [ŋ] sound (like ng in “sing”)
χ: like a hard h, similar to the ch in German “Bach” or Scottish “loch”
stress is on the second syllable: αγ-ΧΩ-θη-κα

Syllables:

αγ–χώ–θη–κα

So you say something like:

ang-HO-thi-ka

with a strong kh / ch sound for the χ.

Could αγχώθηκα also mean “I was stressed” rather than “I got stressed”? What if I want to say “I was stressed for a while”?

Αγχώθηκα is aorist, which is simple past and usually focuses on the event (the change of state):

αγχώθηκα = I got stressed / I became stressed (at some point).

If you want to express ongoing / repeated stress in the past, you use the imperfect:

αγχωνόμουν = I was getting stressed / I used to get stressed / I was stressed (over a period)

Examples:

Χθες στη δουλειά αγχώθηκα.
→ Yesterday at work I got stressed (at some point).
Όλο το απόγευμα αγχωνόμουν.
→ I was stressed all afternoon / I kept being stressed all afternoon.

So αγχώθηκα = event (the moment you become stressed),
while αγχωνόμουν = state or repeated action over time.