English versus English
The American people oft speak the English language. Hmmm how insightful. The English also speak English. The variations between countries are as of yet not enough to constitute a change in the title of one. The mutual intelligibility is greater than that shared with Patois or any pidgin English found around the globe. Nonetheless some sayings are intelligible but might strike a bell of unfamiliarity in the listener's thought processes.
My bias is that I am an American, and these are my observations.
People of the U.K. use the word rubbish where we would say trash or more appropriately litter. They say trainers when we would say sneakers. They say lift when we would say elevator. They say tele when we would say tv. They say snigger when we would say snicker. Seriously.