Which do you prefer , a native English teacher who doesn't hold any qualifications or an experienced and qualified teacher who speaks your language?

A qualified and experienced English teacher is far better than an inexperienced and unqualified native English teacher. Unfortunately it doesn't happen so because of :

* The wrong perception about perfection in language of native speakers. (They use slangs very often which is not accepted Academically)

* Psychological reasons to attract the potential clients as students.

I agree with all the previous answers, far better to have a qualified teacher who speaks your language, as long as they are competent. This is what I would suggest as a general rule, however from time to you will meet non-qualified native speakers who just happen to be "naturals" at teaching but for one reason or other (later in life perhaps?) don't have recognised qualifications.

An experienced and qualified person should fit the position regardless if he/she is native or not.Being a native doesn't mean he/she will be able to teach properly their native language .

Hmmm a tricky question Mr. Gendy.

"A native English teacher who doesn't hold any qualifications" can still be an outstanding teacher & linguist too! And I speak out of experience with many extremely remarkable langauge & teaching talents who have no educational background in education or pedadogy, but a wealth of attained knowledge through extensive reading or some other related profession.

A qualified teacher who speaks a (middle) language is useful in some teaching methods pertaining to first stages of learning a foreign language (while other methods specifically ask for a native speaker). Then again, having the right qualifications does not always guarantee teaching talent, as teaching is all about conveying & sharing knowledge rather having it alone.

I hope this contributes sensibly to your good question.

I feel that an experienced teacher with innovative ideas is much better than an inexperienced native speaker.

I personally100% agree with the answer of Mr. Anayat Bukhari with the addition that I have seen a number of experienced and quaified teachers with excellent and exceptional results than native speakers. 

A native.

English teacher who knows the native language too with the required qualifications would be my choice.

Best answer is a mother language spook persone with experienced and qulified best of best.