Learn Italian: Concludiamo l'accordo, a patto che il pagamento sia veloce. - We conclude the agreement, on the condition that the payment is fast.

The phrase a patto che (on the condition that / provided that) expresses a condition that must be met for the main action to happen. This conditionality requires the subjunctive mood in Italian, so we use sia (the present subjunctive of essere) instead of the indicative è.

Could I use purché instead of a patto che in this sentence?

Yes! Purché and a patto che both mean "provided that" or "as long as," and both trigger the subjunctive. Saying ...purché il pagamento sia veloce would mean exactly the same thing.

What does a patto che literally translate to?

The word patto means "pact" or "agreement." So a patto che literally translates to "at the pact that," which maps naturally into English as "on the condition that" or "provided that."

Can concludiamo also mean "let's conclude"?

Yes! In Italian, the present tense noi (we) form is identical to the imperative (command) form for "we." Depending on the speaker's tone, concludiamo l'accordo can mean "we are concluding the agreement," "we will conclude the agreement," or "let's conclude the agreement."