How can you never be taught grammar? There are two English gcses, English language and English Lit. One is about the technicalities of the language, the other about literature. Everyone has to do English Language....
There are indeed two GCSEs but crucially we had only one type of English lesson. We studied literature, poetry, wrote stories and poems of our own; did presentations, read plays, memorised Shakespearean monologues and such. But, barring that one poem in primary school I was never taught what an adverb is for example.
In French we'd look at past-participles and different tenses but never was it discussed what the pluperfect or future perfect was in English. In Russian we looked at locative and genitive, accusative and nominative cases (and others I'm sure) but in English there was never once a mention that anything such as a grammatical case existed. In school there was never a lesson on the apostrophe - reading Truss's tome [Eats, Shoots & Leaves] recently made me wonder why on Earth I couldn't have been passed something like that as a kid (I was a quite avid reader for many years but alas of course it wasn't written until 2006).
We did look at literary terms like onomatopoeia, alliteration, spoonerism and related concepts - metaphor, rhyming and timbre - that allow for analysis of poetry and prose.
Our English language classes, and exam incidentally, were about English usage and not really the language itself - the construction of language using English as the subject.
Grammar was just not in vogue at the time I feel. I've always felt however that being taught English grammar would have helped foreign language learning immeasurably.
FWIW I got high marks in both English exams (though I felt I was robbed by my teacher confusing me with the boy I sat next to!).