Civil Law: Obligations, Contracts, Real Rights and Family/Inheritance
Core concepts
Candidates must handle the general theory of obligations (sources, performance, breach, extinction), contract formation (offer, acceptance, cause, consent, object), and real rights (ownership, usufruct, servitude, mortgage, possession). Family and succession matters require command of marriage regimes (community of property vs separation), parental authority, and legitimate shares (legítimas) in inheritance.
Traps in questions
Frequent traps: confusing nullity (void ab initio) with annulability (voidable, subject to time limits); mixing ownership with possession; and overlooking that a mortgage is an accessory real right that follows the secured obligation. In family matters, questions test whether property acquired before marriage falls into the community - usually it does not. In succession, the trap is forgetting the legitimate share that heirs cannot be deprived of by will.
Rule of thumb
Nullity is argued by anyone, anytime; annulment must be invoked within the legal period. For real rights, ask whether the right is principal (ownership) or accessory/security (mortgage).
Worked example
A seller transfers ownership but the buyer never registers. As between the parties, ownership passes by valid contract; but against third parties, registration matters. A question asking 'who owns vis-à-vis third parties' tests the registry effect, not the contract.