THERE'S plenty of sobbing and sighing in this Romeo and Juliet. The performers seem determined to convince the audience of their genuine emotions in this most well-known and well-worn of tragic love stories. But as the "pair of starcross'd lovers" move through their familiar story on the Hasty Pudding stage, a curious feeling spreads through the theater--that the show is a farcical shadow of Shakespeare's play. The actors try to sink themselves into the pure emotion of the story and pay no attention to the words they use.

That would be a mistake in any play of Shakespeare's, but Romeo and Juliet suffers cruelly. Shakespeare frolics in the verbal exuberance of his youth in each of the play's celebrated passages. Like Mercutio's "Queen Mab" speech, Romeo and Juliet studies insubstantiality, considering love as the product of words, not acts. After all, there isn't much in the plot to convince an audience of the worth of the love between Romeo and Juliet: a kiss at a masked ball, a nighttime encounter, a secret marriage, and one night together are its only substance.

If the performers of these parts are to convince us of the trancendence of their bond, they must use the one tool Shakespeare gives them--his poetry. Its power is extraordinary, as when it switches from the prevalent formal diction to simple, direct monosyllables in the Act II meeting between the two lovers--so straightforward that its language has become a model for greeting cards and sentimental wallposters. Shakespeare never lets us doubt that the love of Romeo and Juliet is the offspring not of their hearts but of their dreams, their words:

Which are the children of an idle brain,

Begot of nothing but vain fantasy,

Which is as thin of substance as the air...

Romeo sounds this note in his very first speech with the cry of "O any thing, of nothing first create." Characteristically, Walter C. Hughes's Romeo swallows the line.

The blame for the failure of this Romeo and Juliet must lie at the feet of Hughes and Shannon Gaughan as Juliet. Neither goes beyond the broad label of 'youth' to find some more specific trait in their characters to highlight; neither is terribly graceful on stage; and both annoyingly exploit some vocal and some non-verbal mannerisms.

Hughes has a big smile and good looks, but ten lines into his first speech he drops the thread of Shakespearian poetry and never picks it up again. His voice maintains the same pace and tone throughout the show, except at moments of special excitement when he raises it up high in his throat in a doomed attempt to communicate wonderment. When he is banished for killing Juliet's cousin in a duel and flees to his confessor's cell, he collapses on the floor and cries; the irritating sobs continue interminably. They seem an admission of the actor's inability to cope with Shakespeare's writing.

Gaughan is little better, though she has moments of more composure on stage. She seems to be trying to act out a genuinely 13-year-old Juliet, but like Hughes she lacks essential vocal control. She tries to press her small voice to impassioned heights, and the result is an embarrassing sound somewhere between a whine and a scream. And at heated moments, she has a habit of trying to spout an entire line of pentameter verse in one breath.

For a play relying so heavily in both form and content on the power of words to have such an actor and actress in lead roles suggests a failure in direction as well. Valerie Lester's approach to the play is impeccably traditional: not necessarily a flaw, but once more emphasizing the language which is beyond the performers. Lester's pacing of the mostly uncut script is smooth and well-jointed, and a few nice touches--like a drum beat behind the duel scene--relive the general disarray a bit. Her failure lies in the casting of the show, not in the details of its direction.

Only a couple of performances rise above the standard set by the leads. Shirley Wilber's embodiment of Juliet's Nurse seems on another plane from everything else in this production: smooth and completely in control of every nuance of Shakespeare's verse. Her discovery of Juliet's feigned death is the only moment of convincing grief in the whole show.

Jonathan Prince's Mercutio is equally smooth but much less ingenuous. Prince pays attention to what he says, but should learn that the moment of stillness is as valuable to an actor as the gesture. He accompanies each line in the "Queen Mab" speech with a fidget, wave, or wriggle of the hips and ends up irritating instead of captivating. Alexander C. Pearson gives Friar Laurence a good, hammy performance, suitably gawkish, well-intentioned and incompetent, but by the end he gets sucked into the general failure.

One scene in this production succeeds quite well, and also points up the disaster in the rest. When the Capulets discover Juliet apparently dead in her chamber, they explode in a satirical outpouring off grief that Shakespeare wrote to mock the traditional, over-formal conventions of Elizabethan tragedy. Mother and Father Capulet vie in the extravagance of their laments; lines like "life and these lips have long been separated" signal to the audience that this is farce, not tragedy. The cast at the Hasty Pudding conveys the full comedy of this scene. Unfortunately, the comic atmosphere lingers like an unwanted guest till the curtain falls.

Romeo and Juliet is too familiar and capricious a story for actors to rely on the plot alone. They must embody Shakespeare's fascination with the lunatic, the lover, and the poet,' and when they cannot, the play falls from masterpiece to warhorse, from tragedy to farce.