Kindly explain article 1185, 1186, 1187, 1188, 1189 and 1190 of the civil code of the Philippines for my obligation and contracts subject. Give brief examples for each articles. I've read the book of Hector De Leon but I can't understand this articles well, I hope you can help me with this. Thank you!

Here's a link where you can find article 1185 to 1190:

https://www.chanrobles.com/civilcodeofthephilippinesbook4.htm