I'm having trouble shifting my standered it seem to be very tough and not smooth

Did this just suddenly happen or just started getting harder a little at a time Is it the same in all gears A couple of possibilities is trans is low on lube need to check if full drain and replace It could be the clutch system itself Does the pedal feel strong or does it feel real weak Have you checked the fluid level in the clutch master cylinder If it is low add enough to fill to line If that does not help it could be Then we will have to start looking at the master or slave is bad, clutch is bad or trans has a problem