At a national karate tournament on the weekend I had the opportunity to eavesdrop on the conversations of people from all over the country - the perfect way to add a few turns of phrase to my repertoire. At one point I heard a child say to her mother that she had left something behind in the main hall, and the mother told her to go and get it. What mum actually said was "itteoide" - literally "go and come". Nothing strange there - parents often use "oide" to say "come here", and it sounds more natural than "kite". What I noticed was how much easier "itteoide" rolls off the tongue compared to say "ittekite" which would have the same meaning, but which makes the speaker sound like Skippy the kangaroo. And though my romanization has rendered the words as "itteoide", the actual sound is more like "ittoide" - even easier to say.
But what the hell is oide? I looked it up in JEDict and found the phrase oideyasu, which is used in shops to mean welcome (apparently -I have never heard it). I rang a friend and asked her what the kanji for oide was. She didn't know. I struck gold with my Wordtank. Oide is 御出で (おいで). 御 is the polite prefix found on words like 御国 （おくに）your country, or 御中元 (おちゅうげん）midsummer gift, or even 御菓子 (おかし) sweets. The Wordtank explanation revealed that 御出で was the 尊敬語 (そんけいご) respectful form of 行く/来る (いく, go/ くる, come), and was a contraction of おいでなさい. From formal expression to a phrase used with children - just like 御前 (おまえ).
See what you can learn from eavesdropping.