Hello Vany Bunga: Use Either & Or together like so: "The correct answer is either A or B." Use Neither & Nor together like so: "The correct answer was neither C nor D." Okay? Yet is entirely different. Yet is a transitional word that can be used to break up the monotonous rythm in writing or speaking. Here is an example of how I might use it. . "Yet, we may well consider that there are subtle distinctions to be made, because not all subjects are reducible to a simplistic Right or Wrong, or a Black or White conclusion." "Yet, I would like to probe more deeply into the subject, because three relevent issues should be addressed, which are the Existence of a God, the Existence of a Soul, and the Existence of Free Will." [I could give more examples of YET, as a word to introduce a new thought, but lets look at other words which are used to perform the same function. Let's say you wrote a 12 paragraph essay. By the time you get down to paragraph 4, you might begin starting the first sentence of each paragraph with a different word, similar to YET, as follows]: Paragraph 4, begin with YET, [Notice the use of the comma, to indicate a pause in reading or speech] Paragraph 5, begin with, MOREOVER,... Paragraph 6, begin with BEYOND THIS, ... Paragraph 7, begin with NONETHELESS,... Paragraph 8, begin with NOTWITHSTANDING,... Paragraph 9, begin with THUS, ... Paragraph 10, begin with YET,...(again, you see?) Paragraph 11, begin with HERETOFORE, Paragraph 12, begin with THEREFORE, [and here you publish your concluding statement] ....................--Warm Regards, Bruce

hi i actually wanted to answer my self but because its a long grammar story i will give you the website that explains all about it : http://grammar.quickanddirtytips.com/when-to-use-nor.aspx Good luck