conflicts of the Puerto Rican Campaign, Spain ceded Puerto Rico to the United States as part of a peace treaty that brought the Spanish–American War to a sudden conclusion. The United States Army and the early colonial administration tried to impose the English language on island residents. Between 1902 and 1948, the main language of instruction in public schools (used for all subjects except Spanish language courses) was English. Consequently, many American English words are now found in the Puerto Rican vocabulary. English has had a fluctuating status as a second official language of the Island, depending on the political party in power at the moment. The majority of Puerto Ricans today do not speak English at home, and Spanish remains the mother tongue of Puerto Ricans. Stateside Puerto Ricans are known to borrow English words or phrases in mid-sentence in a phenomenon called code-switching, sometimes characterized as Spanglish. Puerto Rican writer Giannina Braschi published the first Spanglish novel, Yo-Yo Boing!, in 1998, a book that represents the code-switching linguistic style of some Latino immigrants in the United States. However, this mixture of Spanish and English is simply an informal blending of languages, not a separate language or dialect, and is not a fundamental characteristic of Spanish or Puerto Rican culture. It is merely an occasional convenience used by speakers who are very fluent in the two languages. Puerto Rico has representation in the Royal Spanish Academy and has its own national academy along with the Spanish-speaking countries of Hispanic America. Accent Puerto Rican accents, both in Spanish and English, could be described as a reflection of Puerto Rico's historical ethnic cultures. Puerto Rican Spanish, like the language of every other Spanish-speaking area, has its distinctive phonological features ("accent"), which derive from the indigenous, African, and European languages that came into contact during the history of the region. The accents of River Plate Spanish (Argentina and Uruguay), for example, were heavily influenced by the presence of Italians in those countries. In the case of Puerto Rico, Spaniards arrived from many regions within Spain and brought with them their own regional dialects/accents. A large number of Spaniards came in particular from a region of southern Spain, Andalusia, and many others arrived from Spain's islands off the coast of North Africa, known as the Canary Islands. When visiting Tenerife or Las Palmas (Islas Canarias, Spain), Puerto Ricans are usually taken at first