Formal or daily English?

English now in days is changing, now we dont have the same formal English as the one spoken on the past, personally I being trying to improve my language because I recognize that my daily language is very far from the formal English  language I should have.  I will try to improve structure of ideas by working on Tell Me More program, I hope that for the end of the this semester my toefl score will improve up to 550, in the same way I will be doing some meetings with my English profesor