I'm studying English Literature at university
Gee, I always wondered where you got those nice words from.... 
Anyway.. sorry, but to be fair, German is a lot more complex and difficult than English (i think it has more words and word combinations as well, I saw somewhere on Wikipedia that german has 9,000,000 words but im not too sure). Both French and Spanish are also more grammatically complex and have a richer vocabulary than english. Italian is easier and simpler than english. But from the wider-spread languages (English, French, Spanish and Chinese) English is the easiest.
The number of 9 million is based on the following (you can read up on it in German only unfortunately, but it's hinted at in Wiki): it's words AND word combinations which artificially inflates the number about 30-fold. A simple example is Dresden, a city in Eastern Germany, not a word per se, just a name, yet listed in that database with 9 million entries total. But not only Dresden is listed, other combos such as Dresden-Altstadt (Dresden Old Town) and others are listed as well. All of them would NOT count as words since they are names and don't contribute to the usable vocabulary. Anyway, it is generally accepted that English has the most words of all languages with an estimate of 500,000 (depending on how you count), German has around 300,000, Latin around 45,000.
As I have pointed out, with English it is rather easy to get to a low level knowledge that affords you the capability of conducting a meaningful conversation - that's part of the explanation for its success as a world language. You don't need a good grasp of grammar and yet most everybody can make sense out of what you're talking about since no inflections or conjugations are necessary to make yourself understood. Even the order of words in a sentence is relatively flexible in English. Try this in German or French and you earn a big fat question mark in response. So, for other languages you need to get to a much higher level of comprehension and mastery until you're able to converse in a meaningful manner.
The difficulty of English (and native English speakers, which I'm not, may not be aware of this) lies somewhere else:
One thing is indeed the richness of the language with the gazillions of words and short mostly monosyllable words that is. So, one difficulty is the huge vocabulary. Another one is the spelling rules (which are very inconsistent to say the least compared to most other languages). And don't get me started on pronunciation rules - there aren't any! In German or Italian or French, once you know the rules, you can read and pronounce ANY text you read in that language. Try that with English! That's why only the English dictionary needs to have a pronunciation key for almost every word listed

So, these are all vocabulary related difficulties.
Another area of difficulty is grammar. Despite its superficial simplicity mentioned above, if you want to speak or write really good English, it gets difficult very quickly. Picking up on the subtle differences you introduce by placing a word before or after another word in the sentence can be a daunting task. Or the stress on words. Just look at this example:
*I* don't think he should get the job.
Meaning: Somebody else thinks he should get the job.
I
don't think he should get the job.
Meaning: It's not true that I think he should get the job.
I don't
think he should get that job.
Meaning: That's not really what I mean. OR I'm not sure he'll get that job.
I don't think
he should get that job.
Meaning: Somebody else should get that job.
I don't think he
should get that job.
Meaning: In my opinion it's wrong that he's going to get that job.
I don't think he should
get that job.
Meaning: He should have to earn (be worthy of, work hard for) that job.
I don't think he should get
that job.
Meaning: He should get another job.
I don't think he should get that
job.
Meaning: Maybe he should get something else instead.
And then all the prepositions - their sometimes interchangeable usage is confusing and sometimes introduces subtle changes in meaning as well.
I'm sure I left out some other things - this much for now
