Why would South Pacific islands have names like Gilbert, Solomon, and Marshall islands prior to being taken by American forces in WWII? (FYI: Googling, it seems these islands did not have different names prior to being taken back by the Americans.)
Because they were discovered by English explorers like James Cook.
Because English explorers made a lot of the discoveries, including Captains Thomas Gilbert and John Marshall. (The islands were actually named after them by a Russian/Estonian admiral.) The Gilberts are now part of the nation of Kiribati, pronounced “Kiribas,” which is how “Gilberts” is spelled in the local language.
“Solomon” of course is not an English name but a Hebrew one. The islands were named by a Spanish explorer who found gold there and believed he had found “King Solomon’s Mines,” the source of the wealth of the biblical king.
Easter Island goes by at least two other names, Rapa Nui and Isla de Pascua. Fiji and Tahiti, despite being swarmed by foreigners, keep their maiden names. But the British and American navies kept plenty busy in the 19th Century.