Japanese has a similarly maddening expression for non-native speakers: "Kekko desu." (けっこです。) For example, if you have coffee and someone asks you if you want milk and sugar... to decline, you might reply "kekko desu" -- which means "it's fine as it is." It's tough to understand when to use it correctly! Still now, after more than 10 years of learning Japanese, I have memorised a few key situations when it is correct/safe to use the expression.