Non-native pronunciations of English result from the common linguistic phenomenon in which non-native users of any language tend to carry the intonation, phonological processes and pronunciation rules from their mother tongue into their English speech. They may also create innovative pronunciations for English sounds not found in the speaker's first language.
The speech of non-native English speakers may exhibit pronunciation characteristics that result from such speakers imperfectly learning the pronunciation of English, either by transferring the phonological rules from their mother tongue into their English speech ("interference") or through implementing strategies similar to those used in primary language acquisition. They may also create innovative pronunciations for English sounds not found in the speaker's first language.
The age at which speakers begin to immerse themselves into a language (such as English) is linked to the degree in which native speakers are able to detect a non-native accent; the exact nature of the link is disputed amongst scholars and may be affected by "neurological plasticity, cognitive development, motivation, psychosocial states, formal instruction, language learning aptitude", and the usage of their first (L1) and second (L2) languages.