Mở trình đơn Apple. Nhấp vào System Preferences… (Tùy chỉnh hệ thống). Nhấp vào Language & Region. Nhấp vào dấu ＋ phía dưới danh sách "Preferred languages" ở bên trái cửa sổ. Chọn ngôn ngữ. Nhấp vào nút Add màu xanh nằm cuối cửa sổ bật lên. Chuyển ngôn ngữ đó lên đầu.

Given the above summary, write a detailed text in English for it.
Click the Apple logo in the top-left corner of the screen. A drop-down menu will appear. You can't change your Safari language settings without changing your Mac's language. It's in the drop-down menu. Doing so opens the System Preferences window. This option is in the System Preferences window. It's under the list of "Preferred languages" on the left side of the window. A pop-up window will appear. Click the language you want to use for Safari. It's a blue button at the bottom of the pop-up window. Doing so adds the language to the "Preferred languages" column. Click and drag the language to the top of the list of languages, then drop it there. This will set the language as your Mac's default language, meaning that Safari will use it as the default language as well.