BertrandRussell
Well you have been given a few answers, maybe you just dont like them?
Those who want but dont get into a grammar school will go to one of the many other types of schools. e.g. Community schools, Foundation and trust schools, Voluntary Aided schools, Voluntary Controlled schools, Grammar schools, Independent schools, Free schools, Academies, University Technical Colleges, Special / SEN schools, Faith schools, Home schooling, etc etc And we then hold the government to account to ensure they are ALL GOOD options.
Personally I would expand selection to create more choice. So not just selection for 'academic' ability, but grammar schools for arts, literature, sports, computers, languages, etc etc and then allow more free movement between them for students who develop their talents at a later stage. Comprehensives can be for students who just want an all around education or haven't developed a strong interest in one area. And there will be no stigma for pupils who don't (or fail to) go to one specific type of grammar because everything becomes more fluid.