NEST - native English speaking teacher

i.e. somebody whose first language is English

NNEST - non-native English speaking teacher,

i.e. somebody whose first language isn’t English

These definitions have been criticised as inadequate. Peter Lahif in this post briefly explains why the term ‘native speaker’ is an unsound recruitment criteria:

Michael Griffin argues in his article that the terms NEST and NNEST only perpetuate stereotypes:

Prejudice against them.

The myth of native speaker superiority.

Discriminatory hiring policies.

Lack of self-confidence.

A ‘look-the-other-way’ attitude from many teaching associations and ELT professionals.

Belief that things will never change.

It’s been the skeleton in the cupboard for way too long.

NESTs (in)directly benefit from the prejudice against NNESTs.

Turning down qualified, experienced and proficient teachers based only on their country of origin undermines professionalism, deprives students of some great teachers and has a negative effect on our profession as a whole.

"The notion of a broader vocabulary range is a myth. Most NSs have no idea of how many words they know or use, and I don’t know of any tables comparing lexical range between sets of NSs or NNSs. A huge mythology is ‘out there." - David Crystal

NESTs are not necessarily good language models

NNESTs can also be good models of pronunciation

There’s no empirical corelation between being a good teacher and being a NEST.