No matter how often or how earnestly we repeat "la-de-dah," some of us simply will never look like Annie Hall. Which makes us about as home at the likes of Classic Clothing as Diane Keaton in the Junior League.

Not, that is, to badmouth that venerabel institution the League, or its landmark Georgetown clothing shop. My treasured (if dated) $10 Pucci, my $4 Anne Klein and a recently acquired slinky black knit number all found their way into my closet via that quaint brick store at 31st and M Streets NW. Friends from out of town - also lost causes in the Annie Hall department - insist on stopping there in preference to the National Gallery.

But while this store sells classics, all right, it's mistake to speak of it and its sister consignment stores in the same breath as stores such as Classic Clothing, which dealing what can only be called period clothing. Though the aspiring Annie Hall may hit a consignment store on a lucky day, don't go there looking for loose vests and baggy, pleated pants. Expect instead to find classics in the safe, tailored sense of the word - someone's cast-off classic designer look.

Never, moreover, was the distinction between traditional thrift stores and consignment stores more clearly illustrated than by the Junior League Shop. Clothes are accepted seasonlly and by appointment only - no heaps of rejects at your neighborhood dump-off point. And they are by no means necessarily accepted: Each potential garment is studied and screened for price and salability before a verdict is reached.

The Junior League Shop (3037 M St. NW), which has been passing on the clothes of socially prominent Washinton women for about 35 years, may well be the grandmommyof class Washington consignment stores.