Is it possible for a foreigner speak with a perfect English accent?
It’s possible but very unlikely that an English person wouldn’t notice at least some foreign accent. Just the same as with any other language… I’m told I have a good accent in French and German, and I do try hard at it, but I’m sure nobody would ever mistake me for a native speaker. As Lily Allen is English, what you say sounds right – British English is a non-rhotic form of the language, which means that the letter r is often not sounded, especially at the end of words. I’m English too and I know that when I say those words, you don’t hear the r. American English is usually rhotic so you would hear it.