There are some non-natives who speak English with a proficiency that may very well exceed that of the average native speaker. Some have taken to calling them pseudo-native speakers. In most situations, it’s extremely difficult to tell them apart from “true” natives. That said, there are some details that could give them away.

The simplest indication could be their accents, which could borrow pronunciation from a number of different regions. In addition, they usually either refrain from using colloquialisms, catchphrases and slang, or use it too much. Importantly, they may also be unaware of some conceptual knowledge usually learned by children during their formative years. Most pseudo-native speakers are also very curt and businesslike in their communication, preferring to eschew small talk. This may appear rude to some. Finally, they have trouble being consistent in their language use and in their judgment of other people’s language use.

Source: Peter Medgyes, “2.3 Pseudo-native speakers”, The Non-Native Teacher

A fun experiment for teachers to do with their students involves accents. An accent is a particular way of speaking that tells you a lot about the speaker (their geographic and social background). The experiment starts out with splitting into groups of three. Then, each person has to speak for 60-90 seconds about a topic of interest while the other two listeners make notes on the speaker’s pronunciation. Then, in order, the groups discuss their findings.

This can be extremely beneficial to both students and teachers, as they’ll be more aware of their accents and be able to better grade language and understand differences between accents and the range of variation. Though there are broad types of accents, each person has his or her own ways of pronouncing things. Being aware of such differences is crucial for teachers.

Source: Ozog, Chris “’I don’t have an accent!’ Said Alison from Sussex” Cambridge University Press, 4 April, 2017, P3