Be able to correctly pronounce the words you would like to speak and have excellent spoken grammar.

Be able to tell whether garments that look good on the hanger actually look good on you.

Be able to defend your arguments in a rational way. Otherwise, all you have is an opinion.

Be able to recognize when you're reading or hearing material biased to your own side.

Be able to cite three good qualities of every relative or acquaintance that you dislike.

Although spoken English doesn't obey the rules of written language, a person who doesn't know the rules thoroughly is at a great disadvantage.