36 natural

37 usage

38 exception

39 particular

40 reference

41 essays

42 colleagues

43 personal

 

44 waht we may find interesting is that it usually takes more words to be polite

 

45 but to a stranger, I probably would say would you mind closing the door?

 

46 there are bound to be some words and phrases that belong in formal language and others taht are informal.