Don't be stupid.別傻氣了。
Don't be so stupid.別這麼蠢了。
When the traffic light turned green, I said to him, "don't be so stupid
from now on. Drive carefully so
that everyone can enjoy a long life."
當綠燈亮時，我對他說：「今後不要這樣笨手笨腳的，開車小心點，讓大家多活幾年。」
It's stupid to keep up with the
joneses.
與別人攀比真是太蠢了。
Don't be stupid. let's go get
something to eat.
別傻了，我們找點吃的吧。