Final answer:
In reported speech, verbs often shift back in tense. The present perfect tense 'has gone' becomes 'had gone' when reported by another person. Peter's statement becomes: Peter said that his sister had gone to France.
Step-by-step explanation:
The student's question involves converting direct speech into reported speech, specifically changing the tense of a verb to match the reported context. In the sentence, 'My sister has gone to France,' Peter is the speaker, and the present perfect tense is used (has gone). When converting this to reported speech, it is customary to backshift the verb tense to the past perfect, which would be 'had gone.' Thus, the final sentence in reported speech would be: Peter said that his sister had gone to France.
Peter's original sentence was in the present perfect tense. In converting it to reported speech, the verb tense shifts to past perfect, changing 'has gone' to 'had gone' in the context of Peter's statement.