In linguistics, the term near-native speakers is used to describe speakers who have achieved "levels of proficiency that cannot be distinguished from native levels in everyday spoken communication and only become apparent through detailed linguistic analyses"[1] (p. 484) in their second language or foreign languages.
Analysis of native and near-native speakers indicates that they differ in their underlying grammar and intuition, meaning that they do not interpret grammatical contrasts the same way.
Late learners who learn a language after the critical period can acquire an accent that is similar to that of native speakers, provided that they have attained relatively high levels of proficiency.
The authors reported that four out of 30 learners were perceived by the native speakers to have achieved nativelike pronunciation.
[4] Second language learners’ pronunciation measured by voice onset time production has also been shown to be close to that of native speakers.
Four out of 10 Spanish speakers who started learning Swedish as a second language at or after the age of 12 years exhibited voice onset time measurements that were similar to that of native speakers when asked to read out Swedish words with the voiceless stops /p/, /t/ and /k/.
[8] The Grammaticality Judgment Test (GJT) is one of the many ways to measure language proficiency and knowledge of grammar cross-linguistically.
[15] In these tests, recordings of speech with varying levels of white noise are played to participants and they are then asked to repeat what they have heard.
[17] The voice onset time (VOT) helps to measure the second language speaker’s proficiency by analysing the participants’ ability to detect distinctions between similar-sounding phonemes.
In studies that employed this method, participants were either required to read aloud words containing the phonemes of interest[5] or determine if the minimal pairs that they heard was voiced or voiceless.
A study on 43 very advanced late learners of Dutch revealed that those who were employed in language-related jobs exhibited nativelike proficiencies.
[1] Language-learning aptitude refers to a “largely innate, relatively fixed talent for learning languages" (p. 485).
Arguments against aptitude as a factor for near-native speakers' proficiency exist in the linguistic field.
Prominent academics like Bialystok[22](1997) argued that coincidental circumstances (social, educational, etc) allow near-native speakers to be proficient in second language(s) and aptitude does not account for their proficiency since they are not "rare individuals with an unusual and prodigious talent" performing "extraordinary feats" (p. 134).
As English-language proficiency tests are usually recognised as the 'make-or-break' requirement in ESL, it becomes a professional duty for NNESTs to improve their English linguistic capacity.