I should have probably clarified, English is NOT an easy language to learn. It's up there with Chinese as being one of the hardest, however, the easiest in itself is not something you can say so simply. According to various studies, the easiest language for an english speaker to learn is Spanish/Portugese, followed by the Germanic languages, like Dutch. However German is a bit more difficult for us.
As i stated ealrier, perhaps not incredibly clearly, is English is a tricksy language. It trips you up frequently, even for a native speaker. The most common mistake that people seem to make though, is the 'there, their, they're' mix-up. All three of them pronounced the same, but with completely different meanings, but it's particularly difficult because one is third-person grouped plural (which happens in few, if not no other languages). The majority of languages just use 'you' as a general reply for third person groups, while English has the term 'them, they, their, they're, theirs etc...'. It also has one of the largest word pools in comparison with other languages, experts estimate that there are over eight hundered thousand words in the english language - If you count all the senses. The average person my age, eighteen, uses between sixteen and twenty thousand of them. English is an awesome language, but SO complex.