Learn Hardcore Greek: Μετά το κούρεμα νιώθω πολύ ωραία και χαμογελάω. - After the haircut I feel very good and I smile.

Μετά το κούρεμα = After the haircut
Μετά το κομμωτήριο would sound like After the hair salon (after being at the salon), which is a bit odd unless you mean “after I left the salon” in a very physical/place sense.

Why do we say Μετά το κούρεμα and not just Μετά κούρεμα without the article?

In Greek, a noun like κούρεμα in this kind of time-expression almost always takes the definite article:

Μετά το κούρεμα = after the haircut (the specific one we’re talking about).

Leaving the article out (Μετά κούρεμα) sounds incomplete or foreign. Greek uses the definite article much more frequently than English does in these “after X / before Y” expressions:

Πριν το μάθημα = before (the) class
Μετά το φαγητό = after (the) meal

What is the difference between νιώθω and αισθάνομαι? Could I say αισθάνομαι πολύ ωραία instead?

Both νιώθω and αισθάνομαι mean to feel (emotionally or physically).

νιώθω is a bit simpler and more common in everyday speech.
αισθάνομαι can sound slightly more formal or introspective, but it’s also very common.

In this sentence you can absolutely say:

Μετά το κούρεμα αισθάνομαι πολύ ωραία και χαμογελάω.

The meaning is essentially the same; the original with νιώθω just sounds a bit more casual/neutral.

Why is it πολύ ωραία and not πολύ καλά? Are they different?

Both are possible, but they have slightly different nuances:

νιώθω πολύ ωραία
- Literally: I feel very nice/great.
- More emotional / subjective: I feel great / I feel really good (in a pleasant way).
- Often used about mood, enjoyment, feeling pleased with something.
νιώθω πολύ καλά
- Literally: I feel very well/good.
- Slightly more neutral; can be physical or general well-being.

After a haircut, πολύ ωραία suggests you feel pleased, happy, maybe confident about how you look.
Πολύ καλά would work too, but it sounds a bit more neutral, like “I feel okay/healthy.”

Why is ωραία in the feminine form when the speaker might be male? Shouldn’t it be ωραίος if I’m a man?

Here, ωραία is not an adjective describing a noun; it’s being used as an adverb meaning nicely / great / very good.

Modern Greek often uses certain adjective forms as adverbs. For the adjective ωραίος, ωραία, ωραίο, the adverbial form is ωραία:

Περνάω ωραία. = I’m having a good time.
Νιώθω ωραία. = I feel great.

As an adverb, ωραία does not change with the gender of the speaker. A man or a woman will both say:

Νιώθω πολύ ωραία.

If you used ωραίος, it would have to modify a masculine noun, e.g.:

Είμαι πολύ ωραίος. = I am very handsome (said by a man).

Does πολύ agree in gender/number with ωραία? Why is it πολύ ωραία and not πολλή ωραία?

Here πολύ is an adverb meaning very, and as an adverb it is invariable: it does not change for gender, number, or case.

πολύ ωραία = very nicely / very great (adverb + adverb).

Πολλή (with double λ and η) is the feminine adjective “much / a lot of,” and would need a noun:

πολλή χαρά = much joy
πολλή δουλειά = a lot of work

So in this sentence, πολύ ωραία is correct because both words are functioning as adverbs.

Why is there no εγώ in the sentence? How do we know it means “I”?

Greek usually drops subject pronouns unless you want to emphasize them, because the verb ending already shows the subject.

νιώθω is 1st person singular: I feel.
χαμογελάω is also 1st person singular: I smile / I am smiling.

So Εγώ is understood from the verb forms:

(Εγώ) νιώθω πολύ ωραία και χαμογελάω.

You would add εγώ only for emphasis, e.g.:

Εγώ νιώθω πολύ ωραία… = I (as opposed to others) feel very good…

How would I say this in the past: “After the haircut I felt very good and I smiled”?

You need the simple past (aorist) for both verbs.

Present:

νιώθω = I feel
χαμογελάω = I smile / I am smiling

Aorist:

ένιωσα = I felt
χαμογέλασα = I smiled

So:

Μετά το κούρεμα ένιωσα πολύ ωραία και χαμογέλασα.

This describes a completed event in the past, just once.

What’s the difference between χαμογελάω and χαμογελώ?

Both mean to smile and are correct; they are simply two variants of the same verb.

χαμογελάω is more common in spoken, everyday Greek.
χαμογελώ can sound a bit more formal or bookish, though Greeks understand and use both.

In the present tense, both sets are possible:

εγώ χαμογελάω / χαμογελώ
εσύ χαμογελάς / χαμογελάς (same)
αυτός/αυτή χαμογελάει / χαμογελά

In this sentence, χαμογελάω sounds perfectly natural and conversational.

Can I change the word order, like Νιώθω πολύ ωραία μετά το κούρεμα? Does the meaning change?

Yes, you can change the word order. All of these are correct:

Μετά το κούρεμα νιώθω πολύ ωραία και χαμογελάω.
Νιώθω πολύ ωραία μετά το κούρεμα και χαμογελάω.
Νιώθω πολύ ωραία και χαμογελάω μετά το κούρεμα.

The core meaning stays the same: after the haircut, you feel great and you smile.

The different orders may slightly shift the focus/emphasis (e.g. starting with Μετά το κούρεμα highlights the time frame), but they are all natural. Greek word order is fairly flexible as long as the relationships are clear.

Is there a difference between Μετά το κούρεμα and Μετά από το κούρεμα, or Μετά που κουρεύτηκα?

They’re all understandable, but there are some preferences:

Μετά το κούρεμα
- Very natural and common.
- Simple preposition μετά
  - noun phrase in accusative.
- Neutral: After the haircut.
Μετά από το κούρεμα
- Also correct, but less necessary here.
- μετά από can sound a bit heavier or more explicit; often used with longer or more abstract phrases.
- Here, most speakers would prefer just Μετά το κούρεμα.
Μετά που κουρεύτηκα
- μετά που
  - verb (clause).
- Literally: After I got a haircut.
- Slightly more narrative, focusing on the action rather than the event noun.

All three can be used, but for this simple, everyday statement, Μετά το κούρεμα is the most straightforward and idiomatic.