"F**k you that scarf doesn't suit you".
"That stripe suit you are wearing makes you look like donkey.'
"Go to hell, and don't bother me".
Many thoughts will be running around the head but barely they make out of mouth. If you really want to hear what is going inside the head of an introvert, you have to really nag them hard. Guess what, more than 95% chances is that you will not hear what they really were thinking. They will filter hard all the thoughts and only the necessary things will come out. They are often sweet tongued. It is really hard to see their angry face as they keep their hot air inside their head.
But, it's not their fault to be keeping their thoughts alone with them. They too want to communicate with world. But they are too much of a shy person to directly reveal it. Often times they will prefer to keep their thoughts to themselves. Other times they are too judgemental of themselves, and think that the views expressed by them might hurt others. They will go alternative ways. Introverts are often the best writers and creative personalities around the globe. But, they are also the most loneliest ones and often tagged with being cold and unresponsive. Be gentle and genuine with them and you will be amazed by their hidden gems. They are often the best friends to have. They naturally have fewer friends circle. So they are really selective about their friends.