In fact, you could say he’s not the sharpest knife in the drawer.
So, what you mean is – he’s stupid. However, we don’t like to be that direct and we frequently prefer to use a more diplomatic style to soften our words (and often to add humour).
In business and indeed life in general, a more diplomatic, subtle language may pay dividends. Learning this skill can be a challenge for non-native speakers, but it is worth doing.
Is diplomacy important in your language or do you just say what you mean?
Click on the image below to read an excellent article that provides some very useful guidelines on precisely this topic.