What are the limits of permissible conversation between a man and his fiancée, for whom marriage and dowry have been agreed upon, but the contract has not been formalized or the dowry paid?

Marriage is not contracted merely by your father saying: "We ask for your daughter So-and-so for my son So-and-so." Rather, there must be an offer and acceptance, such as the woman's guardian saying: "I marry you to So-and-so," and the husband saying: "I accept her marriage." If the offer and acceptance occur, the marriage contract is concluded, and the woman becomes his wife, even if the contract is not documented in court. Otherwise, she remains a stranger to him. These phrases are usually for engagement and not for the marriage contract itself.