Synchromesh - very common on MK4 golfs. It's about $150 - $200 to fix then mechanics labor... but above all, it is a pain.
The noise is the teeth on the flywheel grinding on the teeth of the starter. Check to see if the starter is loose, this is the most common cause of that noise.
You re-engage the starter and you can damage the bendix, or the gear on the starter drive for the engine. It makes a grinding sound and will ruin the starter.
Need a new gearbox. You get a grinding noise only in first gear when you accelerate fast . second gear and the rest should be fine.
broken stsarter or ring gear.
Cause you don't know how to drive
main shaft bearing
You probably have a "throwout bearing" going bad.
The grinding noise can be an indication of a bad gear in the transmission. The grinding noise can also indicate a problem with the clutch.
that means you are letting go of the clutch too fast and possibly grinding gears. Some of us may not know what a car is doing when it's doing a kangaroo. Please describe.
It is the sound of the gears grinding against each other. Because it is at a high speed, it sounds like a rattling instead of a grinding.
you may not be pushing the clutch all the way in or the cluch may need to be adjusted
sounds like a wheel bearing.