Consider the following sentence: You and I should have lunch. Is the correct form of this sentence You and I … or You and me …? This is a common source of confusion in English.
Fortunately, there’s an easy way to decide whether to use I or me in such sentences. All you have to do is drop the word you then try the sentence with I and me one at a time. For example: I should have lunch. Me should have lunch.
Clearly the preferred form in this case is I; thus, the original sentence was correct to use you and I. Here’s another example: He’ll blame you and I. Drop the word you then try the sentence with I and me one at a time, like so: He’ll blame I. He’ll blame me.
You can see that the second of these is correct. This means that the original sentence should have been: “He’ll blame you and me.” Easy.
On a related note, when using phrases such as you and me, you and I or them and us, it has traditionally been considered courteous to place the reference to yourself last. For example, we prefer: “He’ll ask you and me later.” over: “He’ll ask me and you later.”
betterwritingskills: “You and I” or “You and me”?