How old is the grout, and do you know if and how it was sealed?
Also, Terri, you can delete the other copy of this question if you want. Hover your mouse near the right end of the thin line above your post. It should pull up a little arrow. Click on that and find a pull-down menu that should include "delete this post."
Terri...check out this pair of articles I wrote on some grout tips
I wish I had 1/4th the knowledge ya'all do about these things.