So you've mastered rudimentary Russian. It no longer takes you well into the night to wish your neighbors "good morning." You can conjugate a verb faster than it takes to say zdravstvuitye, and you're tacking prefixes onto verbs of motion with abandon.


Sure, you know all these things. But do you really know whom to vy and whom to ty? For those of us who claim English as our native tongue, deciding between using the formal or informal modes can produce more anxiety than a run-in with the local mafia.


Contrary to what our Russian teachers led us to believe, vy-ing and ty-ing is not a formulaic affair. It's a feeling -- you have to cultivate it.


You'll know when you have it. One day you'll wake up and suddenly realize how many native Russian speakers you've insulted with an inappropriate ty. Or you will cringe whenever you overhear some other bumbling foreigner make a similar mistake.


Until you make it up the next rung on the ladder of cultural sensitivity, here are a few ty/vy guidelines to follow. The age factor, for one. All children are definitely ty material. Logically, anyone considerably older than you -- unless it is your grandmother -- is a vy. Where do you draw the line? When does a child grow up? When is someone just too senior to achieve ty status? Damned if I know.


Only two categories of people have the perpetual right of ty: babushkas and cops. If you are over 70 or you carry a badge and -- more importantly -- a gun, you are on familiar terms with the whole city.


Don't be fooled by that myth some of us learned in basic Russian that ty-ing is a bilateral thing -- that is, that once people start ty-ing you, you have the green light to ty them back. Wrong, wrong, wrong. The older generation may find it is their hearts to ty you, but that does not mean you can ty them back.


People approximately your age (give or take a few decades) are potential ty-buddies, but arriving upon ty status is a decision made between consenting adults. Some transitions are smooth -- virtually transparent. Others are rocky. Be forewarned that the longer you vy someone, the harder it is to switch to ty. Just take my friend Alla. It feels like I should be ty-ing her. I ty other members of her family. But every time I try to lighten things up she vys me back. That ty window of opportunity is closed, apparently for good.


Once you make the transition to ty, you're set for life. But beware that some people can use their ty's and vy's capriciously. Take my former landlady, for example. She ty-ed me from the moment she laid eyes on me. But the minute we had a conflict over repairs, it was straight back to vy. I knew I was in big trouble. It took several minutes of coaxing to ease her into ty again.


Many of your Russian friends will assure you that, when in doubt, just ask: Mozhno na ty? But how are you going to know when it is appropriate to ask, and when it isn't? You might risk offense just by posing the question. I myself have often heard this line in action -- each time with successful results.


But I have only heard it while sitting at a table weighed down with copious quantities of alcohol. It probably is a lot less effective when, say, applying for a bank loan.