I am really confused that the whole process of the method of image. Suppose I have the + q near the infinite conducting plane which is grounded. My first question is: Is the conducting plane grounded before putting the +q or after putting the +q then grounded? The first question would lead to my second question. If I have an infinite neutral plane, then I am putting a +q near it, it will induce the negative charge on the plane. Next, I grounded the plane, so the positive charges on the plane will be neutralized (All the positive charges flowing away). After that, what you remain is the induced negative charges on the plane. In another case, I am going to ground the infinite neutral plane first, then put the positive charge near the plane. Can the plane also be induced negative charges? If yes, will the +charges flow away?