The phrase "letted sunlight in" is an example of irregular verb usage in English. The spelling of "letted" comes from the irregular past tense form of the verb "let", which means to allow or permit. The pronunciation of "letted" is /ˈlɛtəd/, with the stress on the first syllable and the "t" sound at the end pronounced clearly. When used in a sentence like "she letted sunlight in", it means that she permitted sunlight to enter the space.