You Never Can Tell, Garrick Theatre, London

Like Wilde's play, the plot of You Never Can Tell revolves around questions of legitimacy and respectability - though for the Clandon children, newly arrived in England after years of exile, the difficulty is not that they haven't been baptised but that they lack a father. This is soon solved by the (none too startling) discovery that the uncongenial Mr Crampton is the man - though this adds new difficulty as they don't like him.

Both Wilde and Shaw depict clever young men and women fencing in speeches packed with wit and paradox; but while Wilde stays on the surface, Shaw points to the passions stirring underneath, and his play is - as Peter Hall's production makes clear - much deeper, more complex and affecting. But it is also far harder to put across.

Shaw himself recognised the play's difficulties of characterisation and casting; a century on, the difficulties have only increased. Pacing Shavian comedy is never easy - the dialogue's brilliance demands speed and lightness, but the ideas need mulling over. And now we have to mentally update them - do the topical points have any contemporary application? In this staging, the long first half often feels wordy and heavy-going.

The pacing problems are exacerbated by Edward Fox's philosophical waiter, the play's moral centre: it's a charming, very funny turn, but at times his tortoise-like delivery slows things down too far. As the matriarch Mrs Clandon, Diana Quick seems surprisingly unwilling to dominate. Otherwise, the casting is excellent: Ryan Kiggell is brilliant as Valentine, the dentist, catching the way Shaw uses dialogue to refract rather than simply express feeling, and is well matched by Nancy Carroll as Gloria. Sinead Matthews and Matthew Dunphy add a note of surrealism as the twins; and Ken Bones brings humanity and depth to Crampton.

The second half moves briskly, and in the final scene Hall discovers a melancholy humour far closer to Shakespeare than to Wilde. By the end, it feels like a highly satisfactory production of a not entirely satisfactory play.

To 11 March (0870 890 1104)