You are look at the page for irregular verb dig
The past perfect tense is used to show that something happened before another action in the past.
The past perfect, sometimes called pluperfect, describes events in the past. This is a specific type of tense and even when it seems hard to use, it is actually pretty easy. This tense describes events that happened in the middle of another event in the past, or which „passed in the past“. To construct the past perfect tense, we need to know all the irregular verbs and their forms.Read more