1991 toyota mr2 shifting problem

I put the transmission into neutral and then I have had great difficulty putting the tranny back into 1st or 2nd but it goes into all of the other gears with no problem. I sometimes have to use two hands and force it into 1st or 2nd. Any ideas, insights or possible solutions to my problem? Please help...thanks.

have you recently put in a new clutch? I had that problem before, however it was only giving me problem in First.. Turn out to be a bad presure plate.. I crack the presure plate in 3 different places.. from a run at the track..