difference between silly and fool and stupid

fool

 noun (мунхаг)

1 a person who you think behaves or speaks in a way that lacks intelligence or good judgment

• Don't be such a fool!
• I felt like a fool when I realized my mistake.

silly

 (маанаг)

• noun

[singular] (informal) often used when speaking to children to say that they are not behaving in a sensible way

• adjective 

sillier, silliest

1 showing a lack of thought, understanding, or judgment

• That was a silly thing to do!
• a silly idea
• Her work is full of silly mistakes.  

      

stupid

 (тэнэг)

• noun

[singular] (informal) if you call someone stupid, you are telling them that you think they are not being very intelligent

•  adjective

 showing a lack of thought or good judgment.

stupider, stupidesthelp more stupid and most stupid are also common

• a stupid mistake
• It was a pretty stupid thing to do.
• I was stupid enough to believe him.
• It was stupid of you to get involved.