Yet - by now, in most cases you can replace those one-for-one Are you there *by now*? Have you been to Brazil *by now*? There is another style that means "something that will or may happen in the future" in this style, you can say things such as: I have yet to go to Brasil. I have yet to take the garbage out. There is an entirely different usage of 'yet' that is an emphatic one, where it can be used as such: We are in a recession, however, there are yet more tourists than last year. And there is stil lone more usage of yet that is the conjunctive usage, that implies 'nevertheless' We are in a recession and yet there are more tourists than last year. Yet is one of those quirky English words that have many many uses, and most native speakers do not even realize that they are using the word in different ways. Mastery of yet is a vivid symptom of a native or naturalized user of English.

Thank you all, you've helped a lot!!

Andrew is completely right - when "already" is used in a question, it has a slightly different connotation. "Have you sent that email yet?" implies that they want you to send the email. You were supposed to have sent the email by now. "Have you sent that email already?" makes the speaker sound a little shocked or surprised. It implies that they might have changed their mind about the email and they want to add something to it. In general, when "yet" is used in a statement, it describes something that has not happened yet, but is expected to happen, or the speaker wishes that it will happen. "I have not yet gone to Brazil." This implies that the speaker will go to Brazil soon, or that they wish to go to Brazil in the future. When it is used in a question, it is asking whether or not someone has done something - but implies that the person is expected to do it, or the person wants them to do it. "Have you sent that email yet?" This implies that the person was supposed to have sent the email, or the speaker wants the person to send the email. Ashley and Andrew have already given great answers ;) I just wanted to elaborate

In addition to what the others have said, "yet" will often be used with negative sentences and questions whereas "already" is often used with affirmative statements. For example: "Have you taken out the trash yet?" - "I have *already* done it" (affirmative statement) versus "I haven't yet done it" (negative statement) They also have slightly different connotations. "Have you sent that email yet?" implies that she asker wants it to be done. "Have you sent the email already?" implies that the asker merely wants to know the status of the email (Maybe they want to add something to it). It is very nuanced though so don't be discouraged if you can't quite grasp the logic. I think you just need to get a feel for it.

In asking questions like that, we use "yet" because we don't know if it has happened or not. "Have you been to Brazil yet?" I have never met you, so I don't know if you have been to Brazil or not. It can be used to imply that you have already done something, if I'm not sure. Example: I run into an old friend I haven't seen in years. She was always planning on visiting Brazil someday. Since it has been a long time since I have seen her, it is very possible that she finally went to Brazil, but I don't know for sure. So I ask her "have you been to Brazil yet?" Another example: I know that my friend is on her way to her mom's house. She is probably already there or very close, but I'm not with her, so I don't know for certain if she is already there or not. So I text her "are you there yet?"