Learn Hardcore Italian: Ringrazio il barista e pago in contanti.

Italian usually drops subject pronouns because the verb ending shows the subject. Ringrazio and pago already mean “I thank” and “I pay.” You add io only for emphasis or contrast, e.g. Io pago, non tu.

Is Ringrazio different from just saying Grazie?

Yes.

Grazie is what you normally say to someone in conversation.
Ringrazio is the verb “I thank” and sounds more formal or narrative. To directly address someone politely you’d say La ringrazio (“I thank you,” formal). Saying just Ringrazio to a person is unusual; use Grazie instead.

Can I replace il barista with a pronoun, like Lo ringrazio or La ringrazio?

Yes.

Lo ringrazio / La ringrazio = “I thank him/her.” This replaces a previously mentioned person (e.g., il barista).
La ringrazio (with capital L sometimes in writing) also means “I thank you” in the formal register, regardless of the addressee’s gender, because it uses the formal Lei.

Why is it il barista and not just barista?

In Italian, singular countable nouns generally take an article. You omit the article mainly after the verb essere when stating someone’s profession: Mio fratello è barista. But when you refer to a specific person, you use the article: il barista (“the bartender/barista”).

Is barista masculine or feminine?

Both. The noun itself doesn’t change; the article shows the gender:

masculine: il barista; plural i baristi
feminine: la barista; plural le bariste

Why is it pago in contanti? Why in?

Because pagare in contanti is the idiomatic way to say “pay in cash.” Italian typically uses:

in for “means of payment” with cash: in contanti, in cash
con for instruments like cards: con la carta, col bancomat

Can I say pago con i contanti?

People will understand, but it’s not the standard idiom. Prefer pago in contanti.

Is contanti plural? Could I say in contante?

Yes, contanti is plural. It comes from an adjective meaning “ready/cash” that’s used as a plural noun. The fixed phrase is in contanti. Singular contante as a noun is rare in everyday speech.

Does pagare need per, like English “pay for”?

No. In Italian you say:

Pagare il caffè / il conto (no per). Using pagare per usually means “to pay the price (for something bad)”: Pagherà per i suoi errori.

Can I specify what I’m paying, like Pago il caffè in contanti?

Absolutely. That’s perfectly natural: Pago il caffè in contanti. If the object is already clear from context, Pago in contanti is enough.

Do I need poi to show the order: Ringrazio il barista e poi pago in contanti?

You don’t need it, but poi makes the sequence explicit. Without poi, e simply links two actions and context normally implies the order.

How do I say what I’m thanking for? Do I need per or di after ringraziare?

Use:

ringraziare qualcuno per + noun: Ti ringrazio per l’aiuto.
ringraziare qualcuno di + infinitive (or per + infinitive, also common): Ti ringrazio di avermi aiutato / per avermi aiutato. You can also use both object and reason: Ringrazio il barista per il caffè.

Should I use tu or Lei with a barista? How does that change this sentence?

Depends on context and local norms. As a customer, using Lei (formal) is safe, especially with someone you don’t know:

addressing the person: La ringrazio. Pago in contanti. With a familiar barista you might use tu: Ti ringrazio. Pago in contanti. In narration about a third person, stick with Ringrazio il barista…

Why does pagare sometimes take an h (e.g., paghi, pagherò) but not here (pago)?

Italian adds h to keep the hard “g” sound before e/i with verbs ending in -gare:

pagare → paghi, paghiamo, pagherò No h is needed before a/o/u: pago, pagano.

Is barista the same as “bartender”? Could I use cameriere instead?

barista = the person behind the bar/counter making coffee, serving drinks, etc. (in cafés/bars).
cameriere/a = waiter/waitress serving at tables. In a cocktail context you might also hear barman/bartender. Use barista for cafés.

Can I change the order: Pago in contanti e ringrazio il barista?

Grammatically yes; it just changes the sequence of actions. Italian word order is flexible, so pick the order that matches the narrative sequence you want.