Many people claim that English is “the hardest” language to learn. Of course, difficulty of language is subjective, a person from Sweden will have an easier time learning English than a person from China. For many people English is very difficult to learn; however, it is not really “the hardest” by any technical definition of the term. English has a low consonant-vowel ratio, Russian for comparison has a high consonant-vowel ratio. English also only has an average consonant inventory, whereas Polish has a large consonant inventory. Though English does have a large vowel quality inventory, as does French, German, and Cantonese.English does not have such linguistics oddities as German, which has, along with only 67 other languages, has two dominate syntax orders. English does not have the adjoined relative clause, like only 10 languages in the world.
English, by and large, is highly average. English is completely ordinary when it comes to language features. It has to be to be a global language. If it was “the hardest” language to learn it would be the second language of choice for most of the world. It has dominated in more countries than almost any other language (French comes in a close second). As people as diverse as Bollywood stars to Chinese diplomats learn English. English is far more universal than Mandarin Chinese (though Chinese has more L-1 speakers than English, it spread is far smaller). English has a fairly simple syntax, a fairly simple (though highly irregular) verb conjugation pattern, few cases, hardly any noun-declension. Though English has pick up a great regional dialects, it has not devolved into Vulgar English, as Latin devolved into Vulgar Latin as it spread over the vast Roman Empire. That fact seems to speak to the relative simplicity of English. If it wasn’t relatively simple, it wouldn’t be a global language.