how do you know when a PDF has been converted to a SVG file

Hi anson lee,

I'm not entirely sure I understand you. What did you convert? How did you convert? Where did you choose greyscale? Did you import the pdf? What does it contain?...
Please, next time, give more info when you ask a question here. It's very hard to give a good answer when we do not have the info needed for this ... :(

Trying my best, I can come up with these two possible problems / solutions:

1.) Did you maybe just use the wrong tool settings of the eraser?
(you can set the eraser to delete every object it touches, or to delete parts of the object, see toolbar when eraser is selected)

2.) Or is your problem this one:

If you import a pdf and then save it as svg, it's become svg. SVG files can hold vector objects and raster images, too.

The contents of your new file could either be a group - then you would have to ungroup or double-click on it to access the single objects inside it.
Or it could be that your pdf just contained a raster image, and that there are no vector objects inside it - and thus, also not in the svg.

There are two quick ways to find out which one is the case:

1. Zoom in as far as you can. Do you see pixels everywhere? If yes, it's a raster image and not a vector object.

2. Hit F2 and click into the picture at different places. Do you see nodes and paths now? If yes, your picture contains vector objects, and you should probably select everything and ungroup using Ctrl+Shift+G.