Glossary of TEFL Acronyms

NNS - Non-Native Speaker: The acronym NNS is far more common in academic writing than in speech. When reading aloud, you'd actually say non-native speaker and not NNS. A NNS of English is a person who learned English after gaining a native command of their mother tongue.

Note that NNS does not give any qualitative information about the upper level of fluency or ability of the speaker's non-native language. A NNS of English could be indistinguishable from a NS.

This term does seem to imply a threshhold lower level of ability, though. Opinions vary, but if the operative term is speaker, then this implies a distinction between a NNS and an L2 learner who has just started.