Highly proficient Native English speaker without a recognised qualification or a Non Native TEFL qualified teacher?

This is the question of all questions and honestly it depends on the teacher itself. Before I started teaching abroad I would have immediantly jumped to answer the question as being obvious. I would have said "Native teacher" all the way; however, now I would say that both could be equally beneficial for your learning- If the Non-native speaker has a nice clear non descript accent they might even be a better choice. Native speakers have a nice fluency to their speaking but honestly many are weak in grammar, where when a non-native speaker masters English they might even been a superior teacher than the native teacher.  The reason so many people prefer the Native speaker is the accent, because this is what people what to replicate.  In a perfect world people  want to speak English seemlessly without anyone realizing it is not their first language, thus the numerous requests for Native speaking English Instructors.

 I have lived and worked abroad and over the years I have met many non-native teachers that have grown up attending American or British Schools and speak with wonderful accents. Unless you asked to see their passports during conversations you would assume they were Native speakers.  

So I think that if you want to improve your English that both types of teachers could be beneficial.  Just do your research on your choice of teachers. Remember when making the choice, It is the accent and speech patterns that you want to immulate and what really makes the difference, not   the teachers nationality or passport.

I support the views of Chassie. The language proficiency is a gift of God. You mat attain it through effort and practice. It is observed that even native speakers of different languages (including English) speak wrong grammatically. 

So we can't prefer one on another. It is a matter of case to case.

native will be better at stage1.

i think that both types are profitable

good

If I want to comunicate and be understtod , I will choose a native speaker.If the goal is academic , I will choose a qualified teacher.If you apply it on babies' learning , you will find that they listen first and make mistakes and then they learn how to overcome mistakes in their mother language.If you want to listen , you had better listen to a native speaker and then correct mistakes by learning it thoroughly.When you listen to an english song for instance , you find that grammar is missing but you can learn new idioms and expressions but if you are going to write an essay , it must be coherent and correct in grammar.Both are needed but yo can determine the stage of each one.

A interesting question...

I have spent3years working as a Language Practioner in the higher & lower levels of government doing interpretation and translation works.

Native speakers are always best, but your teacher needs to have some proof of proficiency viz. passing and obtaining a degree from an university, to show they understand rules of language. 

Also the region where the speaker comes from is vital, as you would want to learn the language in a unspoilt and tarnished form. EG. best places to learn English is in South Africa, New Zealand and Austrailia, and not your England, USA and Canada

In closing a qualified teacher as you put it has the ability to transfer knowledge, which is vital to any learning process. A native speaker will have a larger range of vocabulary, but will have no reasoning in language being taught and transfered.

Qualified non native.. Teacher/ tutor must know about teaching techniques and strategies. Being  native, in my openion, isn't enough.

nativeeeeeeeeeeeeeeeeee