Learn Hardcore Italian: Al tuo invito rispondo sì; brinderemo con tè freddo. - I’m saying yes to your invitation; we’ll toast with iced tea.

Al is the standard contraction of a + il. The verb rispondere takes the preposition a (respond to), and invito is masculine singular (article il), so you get al. If the noun were feminine singular, you’d use alla (e.g., alla tua richiesta).

Can I say rispondo di sì instead of rispondo sì?

Yes. Both rispondere di sì/di no and rispondere sì/no are accepted. Adding di is very common and slightly more idiomatic in careful speech. Avoid rispondere che sì; use rispondere che… only when followed by a full clause (e.g., Rispondo che verrò).

Why does the sentence start with Al tuo invito? Could I say Rispondo sì al tuo invito instead?

Starting with Al tuo invito is a fronting for emphasis and sounds a bit formal or rhetorical. The neutral, everyday order is Rispondo (di) sì al tuo invito. Both are correct; the fronted version highlights the invitation as the topic.

Why is rispondo in the present but brinderemo in the future? Is that normal?

Yes. Rispondo describes what I’m doing now (answering), while brinderemo describes a future plan (we will toast). Italian often mixes tenses this way. If you were deciding later, you could say Risponderò di sì; if the toast were immediate, you might say Brindiamo.

What does brinderemo come from, and why the letter e?

It’s the future of brindare. For regular -are verbs, the future stem changes to -er-: brindare → brinder-. So: brinderò, brinderai, brinderà, brinderemo, brinderete, brinderanno.

Should it be brindare a or brindare con?

Both exist but mean different things:

Brindare a = to toast to someone/something (the reason): Brindiamo al tuo successo.
Brindare con = to toast with a drink (the beverage): Brindiamo con il tè freddo. You can combine them: Brindiamo al tuo invito con il tè freddo.

Do I need an article before tè freddo? Why is it not con il tè freddo?

All are possible, with nuance:

con il tè freddo: specific/the usual iced tea; the most common everyday choice.
con del tè freddo: some iced tea (partitive).
con tè freddo: article-less, a bit concise or “menu style,” still correct. The sentence’s choice is stylistic; many speakers would naturally say con il tè freddo.

Can I say col tè freddo?

Yes, if you mean con il tè freddo. Col is the contraction of con il. You can’t use col when there’s no article (so not with bare tè).

Why is it tè with an accent and sì with an accent?

tè (with grave accent) = the drink; te (no accent) = the pronoun “you” (stressed form).
sì (with accent) = “yes”; si (no accent) is the reflexive/impersonal clitic. The accents distinguish meaning and mark the stressed syllable.

Why is the adjective after the noun: tè freddo and not freddo tè?

In Italian, most descriptive adjectives follow the noun. Temperature adjectives like freddo normally come after: tè freddo, acqua fredda. Some adjectives can precede for style or different nuance, but freddo tè sounds odd here.

Is the semicolon natural here? Could I use other punctuation?

Yes, the semicolon is fine and used much like in English to link closely related clauses. Alternatives:

Period: … rispondo sì. Brinderemo … (more neutral).
Comma + e: … rispondo sì, e brinderemo … (more conversational). A comma alone without a conjunction would be too loose in formal writing.

Does tuo agree with invito? Would it change with a different noun?

Yes. Tuo agrees in gender and number with the noun it modifies:

il tuo invito (masc. sing.)
i tuoi inviti (masc. pl.)
la tua richiesta (fem. sing.)
le tue richieste (fem. pl.)

Could I use a pronoun instead of repeating invito?

Absolutely. You can target the person instead of the invitation:

Ti rispondo (di) sì.
Ti dico di sì.
More idiomatic acceptance: Accetto (volentieri)! or Vengo volentieri! These are very natural ways to accept an invitation.