How come "If you're driving slowly below 10mph and want to stop then press the clutch before the brake so that the car doesn't stall"? In other words, how does the clutch prevent stalling? Thank you!
The engine is connected to the drive wheels through the transmission. In order to continue to run (not stall) an engine needs to turn at a minimum speed (for instance 600 RPM). As a car slows down, the wheels will slow down, eventually to 0 RPM. At some point as you approach a stop, the wheels will turn so slowly that it would force the engine to turn slower than its minimum RPM required to keep running (this would stall the engine).
The clutch disengages the engine from the transmission and thus the drive wheels. This allows the engine to turn at a different RPM than the transmission (which could be potentially 0 RPM if you are stopped). This allows the engine to run with no load at its minimum RPM while the car is travelling very slowly or stopped.