1) islands:groups of islands have plural names with "the".The British isles 2) but an individual island doesn't take "the" 3) cities: the names of cities,towns.villages do not have"the"
1 The Philippines, The Bahamas, The Canaries, The Bermudas 2 Madagascar, Kalimantan, Sakhalin, 3 Moscow, Kapetown, Odessa, Tomsk.......................
еще раз огромное спасибо