First off, the words "unless" and "except" are synonyms, meaning they are similar words. They are both conjunctions, but "except" is also a preposition and a verb (take note of this, but you'll use "except" mostly as a conjunction). The dictionary meaning of "unless" is "except if" or "only if", which simply means: "any other circumstance than" OR "but than" Example 1: "UNLESS his lawyer can prove his innocence, he will stay in jail." Example 2: "He will wait for her, UNLESS she tells him to leave." Example 3: "I won't go to the wedding, UNLESS you come with me." The dictionary meaning of "except" when used as a preposition is: "not including; other than." The dictionary meaning of "except" when used as a conjunction is: "used before a statement that forms an exception to one just made." Pretty much the same thing, right? Example 1: "Everyone was invited, EXCEPT me." Example 2: "Pack all the books, EXCEPT those two." Example 3: "I got everything on the grocery list, EXCEPT the milk." So to sum it up: "unless" is like saying "this wont happen, until another thing is done" and "except" is like saying "everything but that thing was done". I hope this helps.