For those of you who have read Plato's dialogues, you are familiar with Socrates' oft wielded phrase "All I know is that I know nothing." I, for one, would give myself a little more credit than Socrates did himself and say that I know something, but never everything.
Or that is why I have categorized the words and phrases I know into three categories: 1. Words I am sure of, 2. Words that I use but cannot explain adequately and 3. Words whose meaning I am unfamiliar with and would be hard-pressed to translate. I will give you a first-hand example of a category 1 situation: take the pair notario/notary public. I have used the services of both, and I know that they do not serve the same purpose. A notario here in Chile is an attorney and you have to go to a special office to notarize your documents. In the United States, a notary public can be almost anyone who has been sworn as a notary.
We will never know all the words, not even as category 3. However, if we are going to translate a document, the more words and phrases we can confidently say we know as a "category 1", the better we can translate that document.
When you get some free time (as long as it does not disrupt your personal life), take a minute to examine words you're not quite sure about. Maybe you could update your terminology databases and delve into those deep dark meanings you've always wanted to know...
