noun
1
BAD : I was on holiday with my parents on the island Capri.
GOOD : I was on holiday with my parents on the island of Capri.
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the island/isle of + name: 'the holiday resort island of Langkawi', 'the isle of Skye'
2
BAD : Does anyone live in the island?
GOOD : Does anyone live on the island?
BAD : I was born in a small village in Lantau Island.
GOOD : I was born in a small village on Lantau Island.
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When island means 'a mass of land surrounded by water', or is part of a name, the usual preposition is on (NOT in ): 'The prisoners were left on a small island, with neither food nor drinking water.' 'Mr Mandela was placed in a maximum security prison on Robben Island.'
When an island is considered in terms of its people, cities, schools, roads, traditions, economy etc, both in and on are used: 'There has been no serious outbreak of cholera in the island for over twenty years.' 'Elsewhere in the island most of these stone cottages have disappeared.'