Arabic is the language in which the Quran was revealed in and writen in. Arabic is also the language that Allah's last and final Messenger and Prophet peace be upon him spoke in and this the language his sayings and actions have been recorded in
Muslims often use certain Islamic Arabic phrases when they speak even if they do not speak Arabic.
It is essential to get familar with these Arabic Islamic phrases as they are very often used in lectures, books and even day to day speech
This will not only help you blend in more but also help you understand your religion better.