In response to the original post, yes it is possible to teach in private language schools, without a university degree.
In response to the posts that followed, there are a number of awful aspects to living and working in both Spain and the U.K.
People will have different experiences when living in Spain, especially if they are not involved in earning a living in this country.
It would be interesting if somebody could supply the statistics for working British expats and retired British expats in Spain, as I’m sure the majority must be retired or do not need to work.
I agree with deni that it is possible to teach in private school without a university degree.
