A linguist studies language as a system how languages in general work , how specific languages are structured and related , and how it is that people use language . You can do all of this without actually speaking more than one language though polyglottism certainly helps with the study of linguistics , and I ' ve seen certain academic linguists criticized for speaking on the subject of secondlanguage acquisition while themselves being monoglots . Think of it this way a polyglot is to a linguist as a rocket engineer is to a theoretical mathematician . Both skills have lots of overlap , but you can be one without the other . One set is more practical and concrete , and the other set ' s more abstract and academic . Of course , that ' s not to say that there aren ' t practical applications to the academic study of linguistics or the study of abstract math , but it ' s just a metaphor .