The most prominent Polynesian languages, by number of speakers, are Samoan, Tongan, Tahitian, Māori and Hawaiian.

The ancestors of modern Polynesians were Lapita navigators, who settled in the Tonga and Samoa areas about 3,000 years ago.

After that period of shared development, the Proto-Polynesian society split into several descendant populations, as Polynesian navigators scattered around various archipelagoes across the Pacific – some travelling westwards to already populated areas, others navigating eastwards and settling in new territories (Society Islands, Marquesas, Hawaii, New Zealand, Rapa Nui, etc.).

Marck,[10] in 2000, was able to offer some support for some aspects of Wilson's suggestion through comparisons of shared sporadic (irregular, unexpected) sound changes, e. g., Proto-Polynesian and Proto-Nuclear-Polynesian *mafu 'to heal' becoming Proto-Ellicean *mafo.

The table below demonstrates this with the words for 'sky', 'north wind', 'woman', 'house' and 'parent' in a representative selection of languages: Tongan; Niuean; Samoan; Sikaiana; Takuu; North Marquesan; South Marquesan; Mangarevan; Hawaiian; Rapanui language; Tahitian; Māori and Cook Islands Māori (Rarotongan).

Similarities in basic vocabulary may allow speakers from different island groups to achieve a significant degree of understanding of each other's speech.

When a particular language shows unexpectedly large divergence in vocabulary, this may be the result of a name-avoidance taboo situation – see examples in Tahitian, where this has happened often.

However, orthographic conventions for phonemes that are not easily encoded in standard Latin script had to develop over time.

By the time that linguists trained in more modern methods made their way to the Pacific, at least for the major languages, the Bible was already printed according to the orthographic system developed by the missionaries, and the people had learned to read and write without marking vowel length or the glottal stop.

Despite efforts at reform by local academies, the general conservative resistance to orthographic change has led to varying results in Polynesian languages, and several writing variants co-exist.

The glottal stop (not present in all Polynesian languages, but, where present, one of the most common consonants) is indicated by an apostrophe, for example, 'a versus a. Hawaiʻian uses the ʻokina, also called by several other names, a unicameral consonant letter used within the Latin script to mark the phonemic glottal stop.