这两个词都是hang的过去分词。
Ⅰ. hanged 是hang用作“上吊;绞死”时的过去时和过去分词。
① The murderer was hanged this morning. 那个杀人犯今天上午被绞死。
② He hanged himself from a beam in the attic. 他在阁楼上悬梁自尽了。
Ⅱ. hung 是hang 用作“悬挂;下垂”等 意思时过去时和过去分词。如：
① She hung the Christmas decorations on the tree. 她把圣诞节的装饰品挂在树上。
② He hung his head in shame. 他羞耻得垂下脑袋。