What is the most likely reason Peter sounds like a native speaker in French but not in English?

The fact that Peter sounds like a native speaker in French but not in English is most likely due to the order in which he learned the languages. When individuals learn a language at a young age, particularly during the critical period for language acquisition, they are more likely to develop native-like pronunciation and intonation.

If Peter learned French first, this early exposure would have contributed to his ability to mimic the sounds and rhythms of the language more accurately, resulting in his native-like fluency. In contrast, if he began learning English later, he may not have had the same opportunity to achieve that level of pronunciation, as language acquisition becomes more challenging with age.

Other options, such as having traveled to France for several years or having a French parent, could influence his proficiency, but they do not directly address the critical timing and exposure factors that are key in developing native-like pronunciation. The potential lack of practice in English alone does not account for the strong accent; rather, it is the order of acquisition that plays a crucial role in this context. Thus, the emphasis on the sequence of language learning leads to a better explanation for the observed differences in Peter's speaking skills.