[fredjacksonsan]

Fresh transmission fluid may go a long way towards helping with the problem. (Change the filter also)

Do you have a bit more of a description of the symptoms? Does it labor in first gear, seem like it might be in two gears at once, (with much resistance starting off)?

The reluctance to shift can be caused by some worn parts; a shift kit helped one of my older transmissions to overcome this problem.

If none of that solves the issue, you may want to rebuild the transmission, after which it should work for quite a long time for you.