This recording is pretty muddy, too. I have it on both labels, and it is tough to hear about half the words. And the lead singer has good diction, and she is singing in Standard American English, NOT Ebonics! (which wouldn't have been a problem for me, as I grew up (more or less) in The Chicago Ghetto), but may have otherwise been a problem for a British listener.
The other factor is that there are not very many different words used in this song. I realise now, that I've been listening to it for just about 50 years, without knowing about half the words. But, then, I've always admitted that I've never cared about words in songs, only the overall sound. It doesn't matter, in this case, as the gist of this song is clear, - the young lady doesn't want her lover to leave her.