The other day, as I aimed the car along New York Avenue, a deejay aimed the following at me:

"The offer expires tomorrow, except at our showroom in McLean."

He pronounced it "Mc-Clean."

"Rookie, for sure," I thought. "No self-respecting, long-term Washington deejay would bobble that one."

Later in the day, I proved once again that it never rains without pouring. A letter from Charlie Fowler of Upper Marlboro was on the top of the stack. Inside: Fowler's Litmus Test for figuring out which radio announcers are new to the Washington area.

"We can always spot an 'alien,' " Charlie says. Here's what he uses to do it.

VIERS MILL ROAD: Aliens rhyme it with "fires." It actually rhymes with "beers."

SILVER SPRING: Anyone who says "Silver Springs" just got off the boat.

MOUNT RAINIER: Anyone who says "Ruh-NEER" is thinking of the hill in the state of Washington. Charlie and the rest of us say "RAIN-yer."

LA PLATA: Natives of that town in Charles County, Md., wouldn't even raise their heads if you said "La Platta." It's "La PLAY-tuh."

SALISBURY, Md.: Don't tell me, or Charlie, about SALLS-berry steaks. Over on the Eastern Shore, it's SAWLS-berry.

And finally, the one that always separates men from boys, the WICOMICO RIVER. That body of water has probably been pronounced improperly more times than properly. It is not Wick-uh--MICK-oh. It is not WICK-om-ick-oh. It's Wye-COM-ick-oh.

Just in case you got all those right, I've taken the liberty of adding a few more.

BOWIE, Md.: You'd be amazed how many deejays, and others, say BOH-ee. Apparently there's some rock singer named David Bowie who refuses to pronounce it BOO-ee. Shows you how much good rock is.

CHEVY CHASE: The actor by the same name has cleaned this one up considerably. But in the old days -- and to some degree still -- new arrivals pronounced the first word like the car.

FAUQUIER COUNTY, Va.: A lot of deejays must have taken a lot of high school French. They insist on FOH-kee-er. The natives insist on FAW--keer.

And for dessert, these street names in the District of Columbia:

LANIER PLACE NW: Luh-NEER is a calculator company. LAN-yer is the street.

MACOMB STREET NW.: It's muh-COMB, and only muh-COMB.

DE SALES STREET NW.: Once again, high school French won't get it done. It's duh-SALES, just the way it appears, not duh-SALL.

KANAWHA STREET NW.: Resist that impulse to accent the first syllable. It's kuh-NAH-wuh.

And finally, my favorite: HUIDEKOPER PLACE NW.: The easy way to remember it is to ask yourself where a policeman would seek refuge. It's HIDE-a-copper.