Hi WilliamVZ, Well they both can describe a single unit. Each day = every day, as Steven mentions. I would like to add a difference in the usage. "each" can be used as a pronoun to refer to a thing or a person, but "every" can just be a adjective. Each of the cards has a pattern. (correct) Every of the cards has a pattern. (wrong) Every one of the cards has a pattern. (correct) Each one of the cards has a pattern. (correct) Hopefully this helps. :)

hi Endless Learning, (good name by the way) Actually 我这里 not just implies "my place" (extended version the place is belong to you or is related to you, like office), but also suggests that “where I am at the moment”. Situation 1: I'm at my place and don't want my friends come over because of the mess I'll say: 我这里很乱。 Situation 2: I'm at my office and tell my friends how it is. I'll say: 我这里很乱。 To extend the usage: -If the place is related to or belongs to some other person Situation 3: I'm at your place/office and tell you how I feel about the environment. I'll say: 你这里很乱。 See? I change 我 to 你 because it's yours. -If the place mentioned is mine but I'm not at that place right now Situation 4: I'm at your place/office and tell you how is my place I'll say: 我那里很乱。 This time I change 这里 to 那里 because it's not where I am so it should be "there". -What do we say if it's simply a place where I am, and has nothing to do with me? Situation 5: I'm at a bar and tell my friend about it. I'll say: 这里很乱。(But some people do say 我这里很乱。to emphasize the person they're talking to is not here ) Hopefully this explanation helps you. Good luck!