English · Tenses

As the person is speaking in present tense, all verbs should be in present tense, hence it should be "I don't know whom it belongs to.

a) "I found this bangle": This part of the sentence indicates that the speaker found the bangle. It tells us the subject "I" found something, and that something is a "bangle," which is a type of bracelet or ornament worn on the wrist. 

b) "While digging": This part of the sentence provides information about the action of finding the bangle. It tells us that the speaker found the bangle "while digging." So, the discovery of the bangle happened during the process of digging. 

c) "In the backyard": This part of the sentence gives us the location where the speaker found the bangle. The bangle was found "in the backyard," which is the area behind or at the back of the house. 

As the person is speaking in present tense, all verbs should be in present tense, hence it should be "I don't know whom it belongs to.