Well actually actually, everything is even more confusing. Thou was originally the informal way to address someone, think “2nd person singular”. It indicated familiarity, which is why it was used in the translations of the bible. Fast forward a little while, thou falls out of common use. Since the primary place it is still used in is the bible, thou suddenly gets an air of respect and solemnity, very much counter to its actual historical origins. So, by parallel construction:
jij eet een appel = thou eatest an apple
u eet een appel = you eat an apple
gij eet een appel = … ???
As far as I know, there is no simple counterpart in English for “gij”. In modern use, you would use “thou” for “gij”, but then you give up the distinction between je/jij and u… of course you could add english “ye” back to the mix.
But then you read about the history of the T–V distinction in Dutch (http://en.wikipedia.org/wiki/T%E2%80%93V_distinction#Dutch) and realize that originally, there were “du” and “gij/jij”, which then underwent a similar shift to English “thou”/“you”. The “u” is actually a fairly recent development of the language tracing back to around the 17th century and does not have a close counterpart in English.
Who said Germanic languages were not fun?
Bonus fun fact: “jullie” is a contraction of “jij luyden” or “je lieden”, so it is analogous to English colloquial “y’all”. I’ll leave you with that.
I am not an expert, but I think the use of thou / you in modern english follows the same path of tù / vos in the Spanish of South America, Argentine above all, where the comon "tú" in Spain for the 2nd pers. sg. dissapeared in favor of the use of "vos", the old form of "vosotros", that in Spain, in old times, was a very formal and respectful form instead of "tú". In Argentine nowadsys, nevertheless, it is the common form for european Spanish "tú" "vosotros".