In the case of NNEST the language that is spoken is formal or bookish. The local dialects are missing in the language. The pronunciation of the language, vocabulary and the intonation of the language are advantages for the native speakers. They continue to be the perfect language model for the learners. The students however are not able to grasp the practical paradigms associated with the teaching content. In these cases the test scores do not reveal the knowledge of the students. They are limited to the text book content in many cases (Todd and Pojanapunya, 2009).
In many institutions the language knowledge is mistaken to be the subject knowledge of the people (Mahboob, 2010). This causes the teachers with good language skills to have no teaching skills. They do not understand the other cultural context or the cultural constraints. They have not essentially deconstructed the language and they are not able to relate to the students from diverse backgrounds. The students from the diverse background where they do not have English as the native language causes them to feel overwhelmed with the English speaking teacher. This causes the native teachers to be lenient in their approach. They want to relate to the students and hence do not correct their English as much as the NNEST. The native teacher would tend to use dialects that are not grammatically correct. This causes the students to not learn the language properly. They tend to use phrases and the students assume that is a natural form of the language construct. This impacts the productivity of the students.