English is THE easiest language in the world
I'm not so sure about this. All the intricate rules and inconsistencies would make it fairly complex to someone who isn't used to it.
A few things I can think of:
1) Loads of inconsistencies in spelling, pronunciation and grammar: Wind (clock), wind (blows), grower, flower, flour, pour, poor, right, rite, wright, write, cacti, geese, mice, children, teeth, criteria, I am green, you are green, he is green. There is a lot of crap that need to be memorized.
2) Many unintuitive expressions: under the weather, kick the bucket, wild goose chase, piece of cake, bite the bullet, cut corners, beat around the bush, throw caution to the wind, tailor made, last straw, second wind, weather the storm... many, many more.
3) There are almost always multiple ways to say the same thing with very subtle differences: I will speak to him later. I will speak with him later. I will be speaking with him later.
4) We park in the driveway and drive on the parkway. (>_<)
I dunno. I only know English and a decent amount of Vietnamese, so I can't speak for other languages. Aside from being a tonal language, though, Vietnamese is WAY simpler and more direct than English. I would expect a lot of other languages are also.