The standing objection to the study of grammar had led England to carry out a rough experiment on making grammar-teaching in classrooms unfashionable in the 1960s. A rougher ending turned up after students started to work and found, to their frustration, that their English was inferior to the foreigners'. Communication among them fared badly and with foreign companies or governments even worse. This posed a serious problem.
Then, the tide turned, and teachers of grammar were in high demand in the UK . They delivered courses on grammar, punctuation, phonetics to grownups. Big companies such as Marks&Spencer, Tesco, Waterstone's, Unilever and so forth spent dollars after dollars on hiring English teachers to train their employees in the skill of writing correct, grammatical English. And the Royal Post Office was among them too.
This grown-up generation was, indeed, a generation of illiteracy, and they didn't want their children to follow their steps. They protested. At last, in the 1990s, the pendulum swung back to the UK . Her National Curriculum brought the teaching of grammar back into schools after a lapse of 30 years.
However, at the other end of the scale, Americans energetically refined and developed the language all the time to make it more logical and systematic. They pointed out that linguists didn't invent the rules, only they discovered them. All these American developments in the English language have entered the textbooks in the UK and other countries over the world now.