When grammar trips: the misstep of "had went"

What kind of error is it?

This is a grammatical error involving the misuse of verb forms, specifically an incorrect combination of the past participle form of a verb.

Why do people make this mistake?

People often make this error due to confusion between different forms of irregular verbs, mistakenly using the simple past tense instead of the past participle after "had" in past perfect constructions.

What is correct?

The correct form is to use "gone" as the past participle with "had" to form the past perfect tense, resulting in "had gone."