Weight paint problem I'm fairly new to using Blender and have been able to understand most issues on my own but I can't find an answer with this one. 

When I weight paint my mesh's (body, mouth, teeth, etc.) they weight paint just fine but when it comes to the tongue I can't seem to do anything with it. When I click the bone in pose mode and then the mesh and go to weight paint it just looks like how it's shown in the picture.
A couple of things to look at.... 1) is the tongue an object on it's own?   Or a part of another object and it "appears" to be it's own separate object.   2)  I just helped someone else out with this next question/suggestion.   Are the normals pointing in the correct direction or is the tongue drawn inside-out?   Check the normals on the faces.