You pose an interesting usage question that prompts me -- a native English speaker from the USA -- to pause before answering. Here's what I mean by this: Generally speaking, the sound of the language, that is, what one is used to hearing in speech, often influences one's first choice(s) for usage. But does that "gut reaction" mean that other choice(s) are necessarily incorrect? Oftentimes -- yes, but at other times -- well ...??? At these other times, especially when one is looking for "preciseness" of expression and meaning, a dictionary or usage reference must be consulted.
And so, being American, and also being very familiar with how the Usage Panel for my preferred dictionary The American Heritage Dictionary of the English Language (AHDEL) reviews current American usage, I turn to this now to either confirm -- or correct -- my instincts.
Below are the (partial) entries for the words "each" and "every" taken from the AHDEL Fourth Edition:
each PRONUNCIATION: chADJECTIVE:Being one of two or more considered individually; every: Each person cast a vote. My technique improved with each lesson.
every SYLLABICATION:eve·ryPRONUNCIATION: vrADJECTIVE:1a. Constituting each and all members of a group without exception. b. Being all possible: had every chance of winning, but lost. 2. Being each of a specified succession of objects or intervals: every third seat; every two hours. 3. Being the highest degree or expression of: showed us every attention; had every hope of succeeding.
After reading the two entries, what do you think? Is there a subtle difference between the two words?
-I think so. And based on this subtle distinction, I would choose only two of your four sentences for conveying what -- I think -- is the intended meaning. (And here too is something for you to consider: What is the intended meaning?)
But before I divulge which two are my choices, why don't you, based upon a review of the above two entries, first make an attempt?
Student or Learner