I have a fairly new lawn mower and I cannot get it to mulch or bag the grass? I sharpened the blade last season? What should I do?

Make sure the RPM's are at about 3200-3600 and you are cutting no more than 1/3 the total length. When it comes to mulching it is not majic it just clips the grass a little smaller by not letting the clippings discharge. The marketing departments make it look so good.

It is a good idea to mulch, no disposal, the cut clippings hold moisture and the clippings turn to fertilizer. Don't give up it is a little difficult in spring but gets better.
Don

Yeah you can't cut as short when mulching. By the way most manufacturers recommend replacing the blade, not sharpening. The reason for this is that the mettle loses tinsel strength (hardness) and will dull back up quickly. It sounds like you are trying to cut it with the mower set at too low a level. Also your mower may be under powered. Check the owners manuel. Can usually be downloaded on the web.