I recently asked a question and received some great answers, including one that I eventually marked "accepted." I've had this accepted answer for about 7 days now. Today, I found that I had some follow-up questions relating the solution in my accepted-answer, so I posted some comments on the answer. I'm worried that the answer-author may not get notified of my follow-up questions - is there some way I can ensure my comments will be read by that particular user?
It's not uncommon to have some follow-up questions after you solve your first problem with the help of another user. If the questions are minor enough, you may find it acceptable to ask via a comment. Prefixing your comment with @User (where "User" is the users name) will notify that user they have new comments.
If your follow-up question is broad, you may consider posting it as a new question altogether, and letting other people attempt to help you with it. While we befriend some people here and there through their generosity, it's important to note that there are still many thousands of others who are fully-capable of handling your follow-up questions as well, so don't hesitate to create a new question when you feel it's necessary.