In my English book there is a question like:
"What did she do was stupid or silly?" My dictionary shows them as synonyms. So, what's the difference between silly and stupid?
And by the way, is the question correctly written? Shouldn't it be:
"What she did was stupid or silly?"
Stupid is what you think it is. Silly is softer, gentler, almost playfully friendly, at times. A few cultures have words like this, some don't. If you have been forgetful, you can say "I'm silly. I forgot to order the tickets." If your friend has been joking around, you can say: "You're so silly. But seriously, let's get to work." So, silly is rarely seen as insulting, only as a temporary state of mind. Stupid, on the other hand, means a low IQ and no ability to overcome this problem.