The two main groups of languages in Melanesia are Austronesian and Papuan. If you speak an Austronesian language you’re in good company; almost 400 million people are with you. Not that everyone would be able to understand each other, of course, but some popular languages like Javanese (85 million speakers), Tagalog (22 million) and varieties of Malay (12 million) are Austronesian. Austronesian languages even reach as far west as the African island of Madagascar, where 14 million speak Malagasy. (Numbers drawn from the always amazing Ethnologue.com.)
Austronesian languages exist all over Oceania and the Pacific Islands; Hawaiian is Austronesian. New Zealand Maori is Austronesian. Tahitian, Tongan and Marshallese are Austroasian. Of the 400 or so Austronesian languages spoken in Melanesia the most popular is Fijian, with over 300,000 speakers.
Papuan is a language group in the Western Pacific that collects the non-Austronesian and non-Australian languages of the region under one large tent. Since most Australian languages are spoken on the continent of Australia, which is not considered part of Melanesia, for the most part if a language spoken in Western Melanesia isn’t Austronesian it’s Papuan.
For most Melanesian countries, language distribution has everything to do with the colonial past. Fiji has three official languages: English, Fijian and Hindustani. Indigenous Fijians comprise a bit more than half of the population and generally speak Fijian as their primary language. Indo-Fijians make up about 1/3 of the population and are most likely to speak Hindustani. In government, in business and very often in public, Fijians most often communicate in English.
English is the official language of the Solomon Islands but less than 2% of the islanders speak it (). The most common tongue is “Solomons Pijin,” which is a creole language that’s a combination of English and local Kanak tongues. (Is Solomons Pijin “broken English?“) Otherwise, there are 70 living local languages in the Solomon islands; most are Melanesian, but there are a few Polynesian languages spoken in the outlying islands.