You Never Can Tell (Shavian: 𐑿 𐑯𐑧𐑝𐑩 𐑒𐑨𐑯 𐑑𐑧𐑤) is an 1897 four-act play by George Bernard Shaw that debuted at the Royalty Theatre. It was published as part of a volume of Shaw's plays entitled Plays Pleasant.
The play is set in a seaside town and tells the story of Mrs Clandon and her three children, Dolly, Phillip and Gloria, who have just returned to England after an eighteen-year stay in Madeira.
The children have no idea who their father is and, through a comedy of errors, end up inviting him to a family lunch. At the same time, a dentist named Valentine has fallen in love with the eldest daughter, Gloria, who considers herself a modern woman and claims to have no interest in love or marriage.
The play continues with a comedy of errors and confused identities, with the friendly and wise waiter, Walter (most commonly referred to by the characters as "William," because Dolly thinks he resembles Shakespeare), dispensing his wisdom with the titular phrase "You Never Can Tell."
You Never Can Tell has also been performed at the Shaw Festival, Niagara-on-the-Lake, Ontario several times: in 1963, 1973, 1979, 1988, 1995, 2005 and most recently in 2015.
'You Never Can Tell' aired on 'BBC Play of the Month' on October 30, 1977, with Robert Powell as Dr Valentine, Judy Parfitt as Mrs. Clandon and Cyril Cusack as the Waiter[1]·
The CBC broadcast a production in 1973 with Frances Hyland as Mrs. Clandon, Tony Van Bridge as Mr. Crampton, Chris Wiggins as William the Waiter, Maureen Fitzgerald as Gloria, Drew Russell as Valentine and William Osler as Mr. Bohun.