In Argentina, Chile, Uruguay, Paraguay, and some places in Bolivia, Colombia and central America there is a grammar characteristic called “voseo”. In Spanish, the second person of singular, you, is usually “tú”. In these countries, “you” will be “vos” instead. The grammar, syntax and some colloquial expressions of Chilean Spanish are related to Argentinian Spanish.
Either way, the pronoun is not necessary and you can choose not to use it but grammatically, you should pay attention to it. In the Río de la Plata region (including Argentina, Chile, Uruguay and Paraguay), vos has a grammar distinction for some tenses: in present, for instance, you would not say “tú hablas” but “vos hablás”.
In Chile, you would not say “hablás” but “hablái”. The pronoun used can be tú when you know who you’re speaking to, for example, a colleague, or vos, when you have a close relationship with them, your family or boyfriend. This conjugation, along with the form vos, is not taught in school, although it is widely used. As in the rest of Latin America, the second person plural is “ustedes” with the usual conjugation.
Regarding the phonetics of the language, the accent is quite clear and compared to other accents, it sounds quite musical. As usual in South American Spanish, c and z are pronounced like an s, the final s is not often pronounced and the d between two vowels, especially in past participles, disappears.