when a thing goes out of commerce (e.g., when it is expropriated) or when a thing heretofore legal becomes illegal (e.g., during the Japanese occupation, American dollars had become impossible since their use was forbidden by the belligerent occupant)

when a thing disappears in such a way that its existence is unknown (e.g., a particular dog has been missing for sometime); or even if known, it cannot be recovered (Art. 1189[2].), whether as a matter of fact (e.g., a particular ring is dropped from a ship at sea) or of law (e.g., a property is lost through prescription).

when only one party is obliged to comply with a prestation

when both parties are mutually bound to each other

are those which do not impose simultaneous and correlative performance on both parties. In other words, the performance of one party is not dependent upon the simultaneous performance by the other of his own obligation

Is the remedy available to an obligee when the obligor fails to comply with his obligation, to abrogate their contract as if it was never entered into, with the right to recover damages.

Is a future and certain event upon the arrival of which the obligation (or right) subject to it either arises or is terminated. It is a day certain which must necessarily come, although it may not be known when, like the death of a person.

The obligation begins only from a day certain upon the arrival of period.

The obligation is valid up to a day certain and terminates upon arrival of the period.

The obligation is valid when it is provided for by laws

The obligation is valid when it is agreed to by the parties

The obligation is valid when it is fixed by the court.

the period fixed by the parties in their contract which is known as contractual period

When it is fixed or it is known when it will come

When it is not fixed or it is not known when it will come. Where the period is not fixed but a period is intended, the courts are usually empowered by law to fix the same.

Is a month designated in the calendar without regard to the number of days it may contain. "It is the period of time running from the beginning of a certain numbered day up to, but not if there is not sufficient number of days in the next month, then up to and including the last day of that month."

one where two (2) or more of the prestations is due

one where therè are several prestations and all of them are due

one where two (2) or more of the prestations is due.

one where several prestations are due but the performance of one is sufficient

one where only one prestation is due but the debtor may substitute another

one where there is only one (1) obligor or one (1) obligee

one where there are two (2) or more debtors and/or two (2) or more creditors. It may be joint or solidary

one where the whole obligation is to be paid or fulfilled proportionately by the different debtors and/ or is to be demanded proportionately by the different creditors

one where each one of the debtors is bound to render, and/or each one of the creditors has a right to demand from any of the debtors, entire compliance with the prestation

solidarity on the part of the debtors, where any one of them can be made liable for the fulfillment of the entire obligation. It is in the nature of a mutual guaranty

solidarity on the part of the creditors, where any one of them can demand the fulfillment of the entire obligation. Its essential feature is that of mutual representation among the solidary creditors with powers to exercise the rights of others in the same manner as their rights

solidarity on the part of the debtors and creditors, where each one of the debtors is liable to render, and each one of the creditors has a right to demand, entire compliance with the obligation

Where solidarity agreed upon by the parties. If nothing is mentioned in the contract relating to solidarity, the obligation is only joint.

Where solidarity is imposed by the law.

Where solidarity is imposed by the nature of the obligation.

when the parties are bound by the same stipulations

is one the object of which, in its delivery or performance, is capable of partial fulfillment

is one the object of which, in its delivery or performance, is not capable of partial fulfillment

where a specific provision of law declares as indivisible, obligations which, by their nature, are divisible

where the will of the parties makes as indivisible, obligations which, by their nature, are divisible

where the nature of the object or prestation does not admit of division

is one which can stand by itself and does not depend for its validity and existence upon another obligation

is one which is attached to a principal obligation and, therefore, cannot stand alone

when it is provided by law

when it is provided for by stipulation of the parties

when the penalty takes the place of damages

when the penalty imposed merely as punishment for breach

when both the principal obligation and the penal clause can be enforced

is the conveyance of ownership of a thing as an accepted equivalent of performance

is another special form of payment. It is the assignment of all the properties of the debtor for the benefit of his creditors in order that the latter may sell the same and apply the proceeds thereof to the satisfaction of their credits

is the act, on the part of the debtor, of offering to the creditor the thing or amount due. The debtor must show that he has in his possession the thing or money to be delivered at the time of the offer

is the act of depositing the thing or amount due with the proper court when the creditor does not desire or cannot receive it, after complying with the formalities required by law

are the statutory amounts allowed to a party to an action for his expenses incurred in the action

is that currency which if offered by the debtor in the right amount, the creditor must accept in payment of a debt in money

is a sharp sudden increase of money or credit or both without a corresponding increase in business transactions

is the reduction in volume and circulation of the available money or credit, resulting in a decline of the general price level; it is the opposite of inflation

is the place of a person's habitual residence; the place where he has his true fixed permanent home

is the gratuitous abandonment by the creditor of his right against the debtor

one voluntarily adopts or approves some defective or unauthorized act or contract which, without his subsequent approval or consent, would not be binding on him. It indicates an intention on the part of the ratifier to be bound to the provisions of the contract

is the meeting in one (1) person of the characters of creditor and debtor with respect to the same obligation

is the total or partial extinction of an obligation through the creation of a new one which substitutes it

is the extinguishment to the concurrent amount of the debts of two persons who, in their own right, are debtors and creditors of each other

when it will take effect during the lifetime of the donor

when it will become effective upon the death of the donor. It must comply with the formalities of a will

when the object (or cause) or principal conditions of the obligation are changed

when the person of the debtor is substituted and/or when a third person is subrogated in the rights of the creditor

when the object and/or principal conditions of the obligation and the debtor or the creditor, or both the parties, are changed. It is a combination of real and personal novations

takes place when a third person of his own initiative and without the knowledge or against the will of the original debtor assumes the latter's obligation with the consent of the creditor

takes place when the creditor accepts a third person to take the place of the debtor at the instance of the latter. The creditor may withhold approval

is the substitution of a third person in the place of a creditor with reference to a lawful claim or right, giving the former all the rights of the latter, including the right to employ all remedies to enforce payment

deal with norms of good and right conduct evolved in a community. These norms may differ at different times and places and with each group of people

consist of habits and practices which through long usage have been followed and enforced by society or some part of it as binding rules of conduct. It has the force of law when recognized and enforced by law

refers principally to public safety although it has been considered to mean also the public weal

is broader than public order, as the former may refer not only to public safety but also to considerations which are moved by the common good

has a specific name or designation in law

I give that you may give

I give that you may do

I do that you may give

I do that you may do

is a stipulation in a contract clearly and deliberately conferring a favor upon a third person who has a right to demand its fulfillment provided he communicates his acceptance to the obligor before its revocation by the obligee or the original parties.

perfected by mere consent

perfected by the delivery of the thing subject matter of the contract

requires compliance with certain formalities prescribed by law, such prescribed form being thereby an essential element thereof

This includes all the steps taken by the parties leading to the perfection of the contract At this stage, the parties have not yet arrived at any definite agreement

This is when the parties have come to a definite agreement or meeting of the minds regarding the subject matter and cause of the contract , i.e., upon concurrence of the essential elements thereof;

This is when the parties have performed their respective obligations and the contract may be said to have been fully accomplished or executed, resulting in the extinguishment or termination thereof

those that are presumed to exist in certain contracts unless the contrary is expressly stipulated by the parties, like warranty against eviction, or warranty against hidden defects in sale

those without which no contract can validly exist regardless of the intentions of the parties. They are also known as requisites of a contract

the particular stipulations, clauses, terms, or conditions established by the parties in their contract, like conditions, period, interest, penalty, etc., and, therefore, they exist only when they are expressly provided by the parties

is the conformity or concurrence of wills (offer and acceptance) and with respect to contracts, it is the agreement of the will of one (1) contracting party with that of another or others, upon the object and terms of the contract

is a proposal made by one (1) party to another, indicating a willingness to enter into a contract. It is more than an expression of desire or hope. It is really a promise to act or to refrain from acting on condition that the terms thereof are accepted by the person to whom it is made

is the manifestation by the offeree of his assent to all the terms of the offer. Without this, there can be no meeting of the minds between the parties

isone giving a person for a consideration a certain period within which to accept the offer of the offerer

is the period given within which the offeree must accept the offer

is the money paid or promised to be paid in consideration for the option

is a temporary period of sanity

a kind that so overpowers the mind of a party as to prevent him from acting understandingly and voluntarily to do what he would have done if he had been left to exercise freely his own judgment and discretion

is the fraud committed by one (1) party before or at the time of the celebration of the contract to secure the consent of the other. It is the fraud used by a party to induce the other to enter into a contract without which the latter would not have agreed to

which only renders the party who employs it liable for damages because the fraud was not the principal inducement that led the other to give his consent

the act of deliberately deceiving others, by feigning or pretending by agreement, the appearance of a contract which is either non-existent or concealed

when the contract does not really exist and the parties do not intend to be bound at all

when the contract entered into by the parties is different from their true agreement

is the essential reason or purpose which the contracting parties have in view at the time of entering into the contract. It is something bargained for or given by a party in exchange for a legally enforceable promise of another

is the purely personal or private reason which a party has in entering into a contract. It is different from the cause of the contract

is any damage caused by the fact that the price is unjust or inadequate

is that remedy allowed by law by means of which a written instrument is amended or rectified so as to express or conform to the real agreement or intention of the parties when by reason of mistake, fraud, inequitable conduct, or accident, the instrument fails to express such agreement or intention