ALL OF US WILL GO TO THE PARTY, "LESS" MY BOSS

ALL OF US WILL GO TO THE PARTY, "LESS" MY BOSS

The only real way that you are going to be able to stop making mistakes like this is if you expose yourself more to English! When a Spanish speaker says a sentence like this, they are thinking in Spanish either consciously or subconsciously about the word "menos". That is why I hear this mistake quite often.

"Less" is not possible though and the correct word is "except".  So you need to say: "All of us will go to the party except my boss".

​Hope that helps!