Simplify the following text for a Grade 9 native English-speaking person.
Original: Jefferies has also managed Gala Fairydean , Berwick Rangers , Falkirk , Bradford City and Kilmarnock .
Simplified: Jefferies began his managerial career at Gala Fairydean before he joined Berwick Rangers where he was manager until 1988 . He then managed Falkirk FC , Heart of Midlothian FC and Kilmarnock FC .