Myths and misconceptions about the English language.
The English language originates from Latin/Greek/French.
This is actually an extremely common myth in the English speaking world (especially America), but not as common as the myth below. English is actually a western Germanic language, that is related to Dutch, Yiddish, and German. English was highly influenced by two major events in English history:
While the majority of the 1,000 most common and 100 most common words are Germanic, almost all words relating to science, mathematics, and so forth originate from Latin, Greek, most of which came into English via Norman French influence. Out of all of the words available to English speakers, about 28% originate from Norman French, 28% from Latin via Norman influence, and about 25% from Germanic language, including Old English.
Some people would take the majority of total words being of Italic or Romantic origin to mean that English isn't Germanic, but keep in mind that the most commonly used words still are Germanic and English grammar is Germanic as well.
Shakespeare's work is hard to understand because it was written in Old English
Shakespeare actually spoke Early Modern English, and believe it or not, it's far closer to Modern English than Old English. Here's a comparison from the Bible of Old English, Early Modern English, Modern English (the passages are all Matthew 6:9-13; selected because it was the only one I could easily find in all three forms):
As can be seen above, the first 500 years after the Norman invasion English changed a lot, but within the last 400 years since Early Modern English, English hasn't really changed that much. There's definitely one thing that rings true, if Shakespeare spoke Old English, most people wouldn't be able to read it period.
English is the hardest language to learn, for whatever reason.
The first problem with this idea is the idea "hardest from whose perspective?" If someone who speaks a related language like Dutch (English's closest relative), learning English will be a lot easier. However if they speak something like Chinese, which is entirely different, it would be much more difficult. English grammar is actually fairly analytical, straight forward, but like any natural language it does have bizarre quirks that are fairly illogical.
Actually the hardest thing to overcome for most foreigners, especially those coming from non-Germanic or non-Romantic languages is the spelling. Many native English speakers who aren't familiar with other languages tend to believe that English is "spelled the way it sounds." This is hardly the case. There are roughly 41 sounds in English (specifically this amount in American English, but other dialects can have up to 45), yet there are 640+ ways to spell these 41 sounds.
Most other alphabetic languages don't have this problem: for example, languages like Italian, Finnish, and so forth have a nearly 1 to 1 correspondence with spelling and sound. These languages usually take two school years (sometimes less) for a child to learn to spell nearly every word in the language, however English usually takes about eight school years, and even then most people couldn't tell you how to properly spell: acceptable, exhilarate, maintenance, and many other words.
640+ ways to spell 41 sounds (15 of which are vowels, but there's only 6/7 vowel letters) is what makes English hard to learn for many people, especially those not living in English speaking countries. This isn't a glorious system to have either; it'd be like being proud of a dirty bathroom, proclaiming it's the best there is.
French words are pluralized with -s, this is where English gets -s pluralization.
This is actually just a coincidence. The -s ending in English originates from Old English genitive ending -es; the -es ending evolved into -'s, and the apostrophe was later dropped, giving us -s.
Ye is a fancy way to say "the" in Old English, like Ye Olde Shoppe
The word "ye" was actually the plural for "you", essentially the same thing as "y'all", used in some variations of English today. The mistake originates from Dutch printing presses which did not contain the letter þ (th), so the letter "y" was used instead. This created a situation where "ye" (plural you) and "þe" (the) were printed the same way.
Thou and thee are formal and/or fancy ways to say the word "You"
I hear this one a lot when people are talking about language in Shakespeare or crappy translations of the Bible. Thou was actually the singular and information form of "you". "Ye" was the plural and formal way to say "you" (see above). Thou was originally spelled þú, which is related to German du, French tu, and Icelandic þú (Old English and Old Icelandic were fairly close together).
And for the record, "thy" is used before words that start with a consonant, and "thine" is used for words that start before a vowel or "h".