Quintessence... I love that word! But what does it mean?
Well... and here I quote from my Collins Thesaurus:
'Core, distillation, essence, extract, gist, heart, kernel, lifeblood, pith, soul, spirit'.
Mind that these are synonyms, not a definition of the word quintessence. The definition of it in my trusty old Collins Dictionary is far too complicated to write down here, I like the thesaurus ones much better.
Not sure how to pronounce it, is it quin-tessence or quint-essence?

With English being my second language I may be more aware of its difficulty than native speakers.
Leaving the actual pronunciation of words aside for now, (even after all these years, I still can't quite manage the subtle difference of sound between man and men) but how are new English speakers supposed to know the difference between:
Minute (very small) and minute (60 seconds)
Invalid (disabled, feeble) and invalid (untrue, false)
Hamper (to impede) and hamper (a food basket)
Perch (sit or roost) and perch (a fish)

And what about (near) sound-alikes:
Decree - degree
Sole - soul
Marry - merry
indolent - insolent

I remember once asking a friend what a be droll was, she looked at me non-plussed (now here's a word you rarely hear in a conversation, but often see written) "Never heard of it" she said but burst out laughing when I pointed it out in the book I was reading. The sentence went something like this:
'When the soldier arrived at the camp, he threw down his kit bag and unfurled his be
droll and soon fell into dreamless sleep.'
She, being a native speaker, picked it up straight away, the word was obviously broken up in the wrong place, but I had never even heard of the word bedroll, let alone recognise it!

I don't know if it's because I'm a non- native speaker of English, or that I'm just naturally 'picky' but I get really peeved when I hear people say woman instead of women (wimmin) when there's two or more, even I can pronounce the difference! Or say "He's the guy that ...." instead of "He's the guy who..."
And don't get me started on those who don't know the difference between Their, there and they're etc! (or ect!)

There are of course quite a few new immigrants who sell stuff on TradeMe and their use of the language can be the source of a few laughs. (I'm not laughing at them, I'm laughing with them, I made many similar mistakes when I first arrived in NZ)
Frequently miss-spelled words
Dinning table
Bowels (bowls)
Shit (shirt)
Wench (wrench)
Draws (drawers)
Rear (rare)
Botties (booties)
Broach (brooch)
Sequence (sequins)
Defiantly (definitely)