Background: Kenneth Charles Loach (born 17 June 1936) is an English director of television and independent film. His socially critical directing style and socialist ideals are evident in his film treatment of social issues such as poverty (Poor Cow, 1967), homelessness (Cathy Come Home, 1966) and labour rights (Riff-Raff, 1991, and The Navigators, 2001). Loach's film Kes (1969) was voted the seventh greatest British film of the 20th century in a poll by the British Film Institute. Two of his films, The Wind That Shakes the Barley (2006) and I, Daniel Blake (2016) received the Palme d'Or at the Cannes Film Festival, making him the ninth filmmaker to win the award twice.
Context: Loach was born in Nuneaton, Warwickshire, the son of Vivien (nee Hamlin) and John Loach. He attended King Edward VI Grammar School and went on to study law at St Peter's College, Oxford. He graduated with a law degree in 1957. After Oxford He spent 2 years in the Royal Air Force. Loach's ten contributions to the BBC's Wednesday Play anthology series include the docudramas Up the Junction (1965), Cathy Come Home (1966) and In Two Minds (1967). They portray working-class people in conflict with the authorities above them. Three of his early plays are believed to be lost. His 1965 play Three Clear Sundays dealt with capital punishment, and was broadcast at a time when the debate was at a height in the United Kingdom. Up the Junction, adapted by Nell Dunn from her book with the assistance of Loach, deals with an illegal abortion while the leading characters in Cathy Come Home, by Jeremy Sandford, are affected by homelessness, unemployment, and the workings of Social Services. In Two Minds, written by David Mercer, concerns a young schizophrenic woman's experiences of the mental health system. Tony Garnett began to work as his producer in this period, a professional connection which would last until the end of the 1970s. During this period, he also directed the absurdist comedy The End of Arthur's Marriage, about which he later said that he was "the wrong man for the job". Coinciding with his work for The Wednesday Play, Loach began to direct feature films for the cinema, with Poor Cow (1967) and Kes (1969). The latter recounts the story of a troubled boy and his kestrel, and is based on the novel A Kestrel for a Knave by Barry Hines. The film was well received, although the use of Yorkshire dialect throughout the film restricted its distribution, with some American executives at United Artists saying that they would have found a film in Hungarian easier to understand. The British Film Institute named it No 7 in its list of best British films of the twentieth century, published in 1999.
Question: How was it restricted?

Answer:
found a film in Hungarian easier to understand.