Bonin English, or the Bonin Islands language, is an English-based creole of the Ogasawara Islands (informally called Bonin Islands) south of Japan with strong Japanese influence, to the extent that it has been called a mixture of English and Japanese.

History
The Colony of Peel Island was the first permanent settlement in the archipelago. Peel Island (aka Chichijima) was settled in the early nineteenth century by speakers of eighteen European and Austronesian languages, including American English and Hawaiian. This resulted in a pidgin English that became a symbol of island identity. Starting in the 1860s, thousands of Japanese speakers settled the islands, bringing various Japanese dialects along with them. During this time, the pidgin English of the islands creolized among second- and third-generation speakers. The islanders became bilingual, and during the early twentieth century Bonin English incorporated elements of Japanese. Throughout the 20th century, most islanders used Bonin English at home. During the US occupation of 1946–68, the so-called "Navy Generation" learned American English at school, for example developing an – distinction and a rhotic  that their parents did not have. At this time, Japanese residents of the islands were forced to evacuate to the mainland and were not able to return until the Bonin Islands were returned to Japan. After the end of the US occupation, there was an increase in Japanese language education and Japanese residents on the islands. Today, younger residents tend to be monolingual in a variety of Japanese closely resembling the Tokyo standard, with some learning standard English as a foreign language at school. A bilingual spoken dictionary was published in 2005.

Varieties 
Tokyo Metropolitan University linguist Daniel Long has defined the below four varieties of Bonin English used by Westerners on the Bonin Islands.

Bonin Creoloid English 
Bonin English Creoloid is an English-based creoloid used by Westerners on the islands, especially those considered second generation islanders with Pacific Islander ethnic backgrounds. It was brought about due to historically continuous immigration and visits to the islands by English speakers. As there was always contact with native English speakers, it is not considered a creole language with reconstructed grammar, but a creoloid language with simplified grammar and pronunciation.

Bonin Standard English 
Bonin Standard English is an English dialect which has been present since the Navy Generation. Due to the English education provided by the US occupation, the languages on the island became stratified, with Bonin English Creoloid becoming a substrate language and American English becoming the superstrate language. This resulted in a de-creoloidized form of English, Bonin Standard English.

Ogasawara Japanese Koiné 
Before World War II, Ogasawara Japanese Koiné was a koineized form of Japanese spoken among Japanese islanders who spoke various Japanese dialects. While there was a large influence of the Hachijō dialect, as many of the Japanese islanders were from Hachijō island, influence by other Japanese dialects can be seen in some dialectal differences in meaning and speech. Additionally, as Westerners on the islands acquired this koiné as a second language, its influence on the Navy Generation’s speech can be seen in their borrowing of English vocabulary and expressions and usage of non-standard Japanese syntax.

Ogasawara Standard Japanese 
Ogasawara Standard Japanese is a dialect based on standard Japanese. On a basic level, it is included under the Shutoken dialect umbrella, which comprises the Japanese spoken in the Tokyo metropolitan area. However, a considerable amount of names of flora and fauna as well as semantic and pragmatic particularities are characteristic of Ogasawara speech. Even though Westerners still live on the islands, it is common to see only Ogasawara Standard Japanese being spoken within the generations of islanders after the Japanese islanders returned to the islands after the occupation, as many were raised monolingual.

In the time period before World War II and the Navy Generation, English and Japanese varieties were used diglossically. Bonin English Creoloid and Ogasawara Japanese Koiné were used as low varieties, while Bonin Standard English and Ogasawara Standard Japanese were used as high varieties.

Ogasawara Mixed Language 
Characteristic of Bonin English, both Japanese and English syntax and phonotactics are preserved and frequent mixing of both languages in discourse has been recorded. Daniel Long has called this mixed language Ogasawara Mixed Language (OLM). In foundational research on Ogasawara Mixed Language, Long proposed that with the influence of code switching and loan words, there were already many English elements borrowed into the Japanese spoken by native speakers and Westerners on the islands. Additionally, the Navy Generation, raised with Ogasawara Japanese Koiné as their first language, had received an English education at school and interacted with speakers who mixed Japanese and English in their speech, so Japanese and English mixed speech became common. As a result, Long hypothesized that Ogasawara Mixed Language was homogenized and formalized by the time the islands were returned to Japan after World War II.

References 

English-based pidgins and creoles
Languages of Japan
Mixed languages
Japanese-based pidgins and creoles
Bonin Islands