A lot of people say that English is in fact the hardest language to learn out of all. Well, I can't exactly point out to you what the hardest language is since I haven't attempted to learn every one of them. But so far, I think that english is the hardest.
I find that hard to believe. A source would be nice.
I don't have a source but several of my high school teachers and even university professors have said that it's the hardest one. Most people just find that hard to believe since it's the most popular one.
Anyways, I was looking on Wikipedia and there's no concrete answer to which language is the hardest.
Learning a language as an adult strongly depends on the learner's native language. Therefore it is meaningless to make a universal ranking of difficulty. For example, a native English speaker will learn Frisian - and vice versa - much more easily than a native Japanese speaker would. In general, the closer the second language is in relation to vocabulary, sounds, sentence structure, culture, and other factors to the learner's native tongue and culture, the easier acquisition will be.
Hebrew is easy, maybe I say that because it's close to Arabic, I heard Arabic is hard to learn for foreign people, I'd go with Japanese from that list.
Japanese isn't too terrible if you're dedicated. I know a few people who've successfully learnt it, including the characters.