Question

They cut all trees ( change into past perfect tense )
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Answer 1

Answer:

They have cut all trees

Explanation:

.....

Answer 2

Answer:

They had cut all trees.

Explanation:

Here, past participle of cut is cut... So, it doesn't change!

The pluperfect, usually called past perfect in English, is a type of verb form, generally treated as one of the tenses in certain languages, used to refer to an action at a time earlier than a time in the past already referred to. Examples in English are: "we had arrived"; "they had written".