ELICIT, ILLICIT

Elicit means to extract or draw out; illicit means not legal.

EVERYONE, EVERY ONE

Everyone means every person in a group; every one means each person and is always followed by "of".

"Everyone needs to know how to swim."

"Every one of you should be able to swim."

FAIR, FARE

Fair means average, good-looking, pale, unbiased (what a lot of meanings for one little word!); fare is the money you pay to go somewhere by bus, train, plane, taxi, etc. It can also refer to a passenger. As a verb it means do, as in:

"I didn't fare as well in my exams this year as I'd hoped."

FAZE, PHASE

The most common error is the use of phase when the writer means faze. To faze someone is to fluster or confuse them, whereas phase is mostly used in reference to a stage in someone's life--though it can be a stage in almost anything else:

"Like most children, Danny's going through a phase of refusing to eat his vegetables."

"Nothing fazes my mother, who can produce a meal for unexpected guests at a moment's notice."

FOREWORD, FORWARD

Foreword is the preface in a book, usually written by someone who is not the author; forward means ahead, near the front.

FORTH, FOURTH

Forth means forward; fourth is after "third".

FOUL, FOWL

Foul can mean dishonourable (by foul means), disgusting (a foul smell), entangle (rubbish dumped in the river can foul fishing lines); fowl is a bird.

GORILLA, GUERRILLA

Gorilla is a large ape; guerrilla is a particular kind of soldier.

HANGED, HUNG

A criminal is always hanged; a picture is hung:

"We hung the portrait where everybody could see it."

"John Smith was hanged yesterday at dawn."

Just remember, "I'll be hanged if they're going to hang me," and you won't forget the difference again!

HERD, HEARD

Herd is a group of animals; heard is the past tense of hear.

HERE, HEAR

Here refers to a location (as in "over here"). Hear is always what your ears do. I can't see why writers should get confused here, but they must do because I have seen this more than once. (And, no, that's not a sample sentence!)

IRREGARDLESS, REGARDLESS

There is no such word as irregardless; the correct word is regardless.

HOLE, WHOLE

Hole is an opening; whole means complete.

ITS, IT'S

This is confusing because possessives normally have an apostrophe, but in this case it's is short for it is and its is possessive--always.

"Its colour is green and it's quite beautiful."

Other possessives that don't have an apostrophe are theirs, hers, yours and his--though I doubt anyone is likely to try putting one in his!