Short answer. No. Article 1199 requires a person alternatively bound by different prestations to completely perform one of them. The creditor cannot be compelled to receive part of one and part of the other. So the other side must deliver one thing in full — not a mix of both — unless you agree to accept a combination.
What the law says
A person alternatively bound by different prestations shall completely perform one of them.
Civil Code, Article 1199 — Alternative Obligations Need One Complete Performance. Read the full provision →
What the law says
The creditor cannot be compelled to receive part of one and part of the other undertaking.
Civil Code, Article 1199 — Alternative Obligations Need One Complete Performance. Read the full provision →
One complete performance, not a blend
Article 1199 addresses exactly this. It says that a person alternatively bound by different prestations shall completely perform one of them, and that the creditor cannot be compelled to receive part of one and part of the other undertaking. An alternative obligation gives the debtor a menu — deliver thing A or thing B — but it does not let him assemble his own dish from both. He must carry out one of the alternatives in full. Handing over half of A and half of B is not performance of either, and you, as creditor, cannot be forced to accept that patchwork in place of one complete prestation.
Why partial-of-each is not allowed
The rule follows from what an alternative obligation is. The parties agreed that the creditor would receive one of the identified things, whole. Each alternative was meant to be a full, self-contained performance; none of them was a set of fractions to be combined. Allowing the debtor to deliver part of one and part of the other would give the creditor something he never bargained for — a hybrid that may be worth less, or simply be useless, compared with either complete option. It would also let the debtor reshape the obligation unilaterally. Article 1199 keeps the choice limited to whole alternatives.
The choice is between options, not within them
It helps to separate two things: the right to choose which prestation, and the manner of performing the one chosen. In an alternative obligation the debtor — unless the parties gave the choice to the creditor — picks which of the alternatives to perform. What he does not get is a right to perform them piecemeal. Once an option is selected, it must be delivered completely, in accordance with the terms of the obligation. The freedom the law grants is a freedom to elect among options, not a freedom to dilute or fragment the performance the creditor is entitled to receive.
You can still agree to a combination
Article 1199 protects the creditor; it does not bind him against his own wishes. Because the rule is that the creditor cannot be compelled to receive part of one and part of the other, nothing stops you from voluntarily accepting a mix if that genuinely suits you. If the debtor proposes delivering some of each and you are content with it, the two of you can agree to that, and the arrangement holds by consent. The point of the article is that such a combination cannot be forced on you — the default entitlement is to one complete performance of a single alternative.