The shift from American to English can be seen in a change Lennon made to McCartney’s original opening lines. McCartney’s version was, “She was just seventeen/Never been a beauty queen”. Lennon changed it to the more provocative, “She was just seventeen/You know what I mean.” The new line is at once both direct and indirect. Direct: English doesn’t get much more direct than five one-syllable words. Indirect: the listener is drawn complicitly into the world of the the singer. They have to know the code.
“[I]t called the bluff of the chintz-merchants of Denmark Street with their moody misunderstood ‘Johnnies’ and adoring ‘angels’ of sweet sixteen (the legal age of consent). By contrast The Beatles’ heroine was seventeen, a deliberate upping of the ante which, aided by Lennon’s innuendo in the second line, suggested something rather more exciting than merely holding hands. But the clincher for the teenage audience was the song’s straight-from-the-shoulder vernacular. Its hero’s heart didn’t ‘sing’ or ‘take wing’ when he beheld his lady love; this guy’s heart ‘went boom’ when he ‘crossed the room’ – a directness of metaphor and movement.”
The picture at the top is from the website Beatles Autographs, and is used with thanks.