Generative AI proposes several large language models (LLMs) to automatically generate a message in response to users' requests. Such scientific breakthroughs promote new writing assistants but with some fears. The main focus of this study is to analyze the written style of one LLM called ChatGPT by comparing its generated messages with those of the recent French presidents. To achieve this, we compare end-of-the-year addresses written by Chirac, Sarkozy, Hollande, and Macron with those automatically produced by ChatGPT. We found that ChatGPT tends to overuse nouns, possessive determiners, and numbers. On the other hand, the generated speeches employ less verbs, pronouns, and adverbs and include, in mean, too standardized sentences. Considering some words, one can observe that ChatGPT tends to overuse "to must" (devoir), "to continue" or the lemma "we" (nous). Moreover, GPT underuses the auxiliary verb "to be" (^etre), or the modal verbs "to will" (vouloir) or "to have to" (falloir). In addition, when a short text is provided as example to ChatGPT, the machine can generate a short message with a style closed to the original wording. Finally, we reveal that ChatGPT style exposes distinct features compared to real presidential speeches.

翻译：生成式人工智能提供了多种大型语言模型（LLM），可根据用户请求自动生成消息。此类科学突破催生了新型写作助手，但也引发了一些担忧。本研究的主要目的是通过比较ChatGPT生成的消息与近期法国总统的演讲，分析这一大型语言模型的写作风格。为此，我们对比了希拉克、萨科齐、奥朗德和马克龙撰写的年终致辞与ChatGPT自动生成的文本。研究发现，ChatGPT倾向于过度使用名词、所有格限定词和数字。相反，生成的演讲中动词、代词和副词使用较少，且句子平均标准化程度过高。在特定词汇方面，可观察到ChatGPT倾向于过度使用"必须"（devoir）、"继续"或词元"我们"（nous）。此外，GPT对助动词"是"（être）或情态动词"将要"（vouloir）、"必须"（falloir）的使用则显不足。另外，当向ChatGPT提供简短文本作为示例时，机器能生成风格接近原始措辞的短消息。最后，我们发现ChatGPT的风格展现出与真实总统演讲截然不同的特征。