Answer:
Due to tones, common vocabulary, history and education.
Step-by-step explanation:
People say what they have heard. Each language has different words, ways of expressing themselves, swear words, intonation, sounds and history. For example, an indigenous person who speaks a local language, most likely is not rude, because in his tribe it is a sacrilege, besides his lexicon does not have such words. On the contrary, a language such as English or Spanish, which is constantly changing and evolving, due to the number of people who speak it and the importance they have in the world, contains more words, variation and therefore, the ability to speak (more rude, ruder people, or well educated). History also plays an important role, as it has culture behind it all. A romantic language like French has European and Renaissance history that has a passive or educated culture, as the speakers of the time had such characteristics. Whereas, a Eurasian language, such as German or Russian, has more aggressive intonations, and therefore, the people seem more aggressive or lively, because their history is of people in the past with such characteristics.