Clutch peddle won't engauge
Most of these models have a mechanical clutch linkage which can stretch or even break over time. Have that checked. It could also be the clutch itself.
MK3s have the infamous auto-adjusting clutch cable. You can visually inspect the cable where it attaches to the clutch lever on the transmission. If there is slack in the cable, replace it. If it is taught, the problem is probably internal to the transmission. You can (gently and carefully) remove the green end cap on the transmission and inspect the throw-out bearing while manually moving the clutch lever. If it appears to be actuating properly, the clutch has failed...and will need replacement.
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