Please refer to Civil Code of the Philippines (Obligations and Contracts) to answer the following.

1. Explain and differentiate to each other the four kinds of defective contracts.

2. J.C. Construction (J.C.) bought steel bars from Matibay Steel Industries (MS1) which is owned by Buddy Batungbacal. J.C. failed to pay the materials worth P500,000 on due date. J.C. persuaded its client Amoroso with whom it had receivables to pay its obligation to MSI. Amoroso agreed and paid MS the amount of P50,000. After two (2) other payments, Amoroso stopped making further payments. Buddy filed a complaint for collection of the balance of the obligation and damages against J.C. J.C. denied any liability claiming that its obligation was extinguished by reason of novation which took place when MSI accepted partial payments from Amoroso on its behalf. Was the obligation of J.C. Construction to MS extinguished by novation? Why?

3. Distinguish consensual from real contracts and name at least four (4) kinds of real contracts under the present law.