'You Know'

VI, watch the episode of NCIS called "DOA", its reasonably accurate.

Basically the effects of thallium (especially radioactive thallium) are what you tipically imagin radiation sickness to be. Loss of hair, vomiting, killing white blood cells, loss of fluids ect. I belive its what was used to kill that russian in the UK. As far as i know the reason its so dangerious is that it can be absorbed straight through the skin. The only treatmen is prussion blue

Pottassium is just as leathal (if not more so) but unlike thallium OUTSIDE the body its compleatly harmless as it is if injested.
Surely "you know" is just "did/do you know" that has been shortened...
"you know what really annoys me..."
"do you know what really annoys me..."
I think it's really:
  • Aren't you just dying to know what really annoys me? You've got no choice, since I'm going to tell you anyway.
This is an abbreviation of exempli gratiā, a Latin phrase.
Why do we need to use abbeviations from greece or latin?

..and how are we expected to spell abbrivitation?

(and my teacher told me I ask stupid questions F*K not)
Why do we need to use abbeviations from Greek or Latin?
We don't use Greek abbreviations. Greek words are written in the Greek alphabet. Most people can't read or write it any more, and even if they could it's a hassle to reconfigure your keyboard. :)

Latin was the first language to be written in the Latin alphabet (duh!) so the monks who were doing all the writing developed abbreviations for common scholarly expressions as a way of making their jobs easier. Before the invention of the printing press most people had no need to be able to read and write, so it was all up to the monks and government officials.

When the Roman Empire collapsed, Latin continued to be the language of scholarship so scholars kept using those abbreviations. When the printing press was invented, people who never learned Latin learned to read and write, so a significant amount of material began to be printed in other languages. But by then the old abbreviations had been so thoroughly established for 1500 years, that scholars kept using them and so did printers. Nobody bothered inventing abbreviations for the equivalent terms in their national languages.

Today we have a choice, and many English phrases have replaced the Latin ones, or at least stand side by side. We can say "and so forth" instead of et cetera, "in other words" instead of id est, "for example" instead of exempla gratia, "and others" instead of et alii. But we have still never bothered to invent abbreviations for those terms. We still write etc., i.e., e.g., and et al. "Et cetera" is so well known that we actually read it in Latin, but hardly anybody knows what the others stand for, so we usually translate them into English when we say them out loud.

In writing you're free to use "for example" and "and so forth" instead of the Latin abbreviations, and many writers do. But there are still no abbreviations for them in English. You have to write the whole words out.

That's why we use the Latin abbreviations. It's easier than writing the words out. :)

Of course if you speak German you've got it made. They compulsively translate practically everything into German. Instead of etc., Germans write usw for und so weiter.
Don't we translate "i.e." as "that is"?
That's a literal translation of id est. But in vernacular speech, and even in non-academic writing, we often say/write the figure of speech "in other words" instead.

But either way is okay. What is NOT okay is that perhaps most people don't know the difference between "i.e." and "e.g." After "i.e.", you provide a word or phrase that is an exact equivalent or definition of the original, which could even be a short, complete list. After "e.g.," you give one or more examples; a short list but NOT a complete list.