Learn Hardcore Italian: La parrucchiera mi taglia i capelli da anni ed è molto seria. - The hairdresser has cut my hair for years and is very professional.

So the natural phrasing is mi taglia i capelli.
Taglia i miei capelli is grammatically possible but sounds marked or contrastive (e.g., emphasizing “my hair, not someone else’s”), and is much less idiomatic in neutral contexts.

What does mi do here—direct or indirect object?

Mi is an indirect object pronoun meaning “to/for me” or “on me.”
The direct object is i capelli (what gets cut).
Compare:

Mi taglia i capelli. = She cuts my hair (for me).
If “hair” is already known, you could say Me li taglia (“She cuts them for me”): mi = to/for me (indirect), li = them (direct).

Why is the present tense used with da anni? In English I’d say “has been cutting for years.”

In Italian, when an action started in the past and still continues, you normally use the present tense with da + duration:

Mi taglia i capelli da anni. = She has been cutting my hair for years.

You can also say:

È da anni che mi taglia i capelli.
Sono anni che mi taglia i capelli.

What’s the difference between da anni and per anni?

da anni = for years and still ongoing up to now.
- Mi taglia i capelli da anni. (She still does.)
per anni = for years as a span (often seen as finished or not tied to “now”).
- Mi ha tagliato i capelli per anni. (She did for years, not necessarily anymore.)

Can I say mi ha tagliato i capelli da anni?

No. Da with a continuing action pairs with the present: mi taglia i capelli da anni.
Use the passato prossimo with per for a finished period: mi ha tagliato i capelli per anni (implying it may be over).

Why ed è instead of e è?

Ed is just e with an added “d” for euphony before a word starting with a vowel (here, è). Both e è and ed è are correct; ed è often sounds smoother and is common in writing. In speech, many people simply say e.

Where do pronouns go? Is mi può tagliare and può tagliarmi both correct?

Yes. General rules:

Before a conjugated (finite) verb: mi taglia, mi può tagliare.
Attached (enclitic) to an infinitive/gerund/imperative: può tagliarmi, sta tagliandomi, tagliami!

Incorrect: placing mi after a finite verb in normal statements (e.g., ✗ taglia mi i capelli).

Why seria and not serio?

Adjectives agree in gender and number with the noun they describe. Parrucchiera is feminine singular, so the adjective is seria.
If it were masculine: Il parrucchiere … è molto serio.
Note: molto here is an adverb modifying an adjective, so it stays invariable (molto seria/serio).

Does seria mean she isn’t funny?

Not necessarily. In Italian, serio/seria often means “professional, reliable, conscientious.” It can suggest she takes her job seriously, not that she lacks a sense of humor. Synonyms in this context: professionale, affidabile, scrupolosa, precisa.

Is capelli always plural? When would I use capello?

For head hair collectively, Italian uses the plural i capelli (“hair” in English).
Un capello = a single strand of hair.
You’ll also see mass nouns like capigliatura (the head of hair), but in everyday talk i capelli is standard.

Do I need the article in i capelli? Can I omit it?

Use the definite article with body parts: i capelli, le mani, la testa.
Omitting it here (✗ mi taglia capelli) is ungrammatical. You may omit it in certain descriptive patterns (e.g., ha capelli lunghi = “has long hair”), but not in this verb-object structure.

Why is it tagliare i capelli a qualcuno and not di qualcuno?

The idiomatic construction is:

tagliare [art.+ body part] a [someone] → tagliare i capelli a Maria. Using di in this structure (✗ tagliare i capelli di Maria) is not idiomatic for the action. You can use di for possession in a noun phrase: i capelli di Maria (“Maria’s hair”), but not with the verb “to cut.”

What’s the difference between parrucchiera and barbiere?

parrucchiere/parrucchiera: hairdresser; today commonly for all genders and services (cuts, color, styling).
barbiere: barber; traditionally men’s haircuts and shaving/beard services.
A woman working as a barber may be called barbiera, but parrucchiera is far more common.

Can I say Mi sta tagliando i capelli da anni?

No. The progressive (stare + gerund) focuses on an action in progress right now, so it clashes with da anni (a long ongoing span). Use the simple present: Mi taglia i capelli da anni.
Use the progressive for the present moment: Mi sta tagliando i capelli = She is cutting my hair (right now).

Can I front da anni or change the word order?

Yes, for emphasis you can say: Da anni la parrucchiera mi taglia i capelli ed è molto seria.
Clitic mi must still go before the finite verb (unless attached to an infinitive/gerund/imperative). You cannot say ✗ taglia mi i capelli.