When to use different endings in Korean? Can you please explain difference between and when to use these endings: 십니다 (Ex. in book: 나 는 커피를 마십니다. I trasnlated as "I coffee drink/ I am drinking coffee.") 입니다 (Ex. in book: 자는 브라질 학생입니다. I translated as "I Brazil student is(am)/ I am Brazil student") 합니다 (Ex. in book: 마리아는 한국어를 공부합니다. I translated as "Mary/Maria Korean study(ing)//Mary/Maria is studying Korean") Is 입니다 'to do'? 입니다 'to be'? 십니다 ???