Xian borrowed from Yanee Php 5,000. As Xian's security for the debt, Xian promised to pledge his diamond ring to Yanee. Before the delivery of the ring to Yanee, the contract of pledge is not yet perfected. If Xian later on refuses to pledge the ring, Yanee can demand the payment of the obligation although it is with a period. But Yanee cannot require Xian to deliver the ring as security because there is no real contract of pledge yet. There is merely a consensual contract to constitute a pledge. What exists, is a personal right, the right of action on the part of Yanee to demand the constitution of the pledge.

What are the elements of contract present in this case? Identify each?