How will I know if my clutch is worn out?

If it is hard to shift between gears or if it 'pops' out of a gear. Also, you may notice that the clutch feels looser over time. I bought my car used and I had to replace it almost immediately (as well as a few other expensive parts). For me, it popped out of fifth on the freeway. I had to hold it into place the entire way to the shop. Once it was replace, the clutch was unbelievably tighter than before.

when your car is in 3rd and 4th gear at a lower speed jam on the gas. if the rev's go up and the car doesn't speed up then your clutch is beginning to wear out. time to get it checked or possibly replaced. if this starts happening checking it sooner is much better. my clutch did this and i continued to drive it and the clutch blew out on the freeway and trust me that the last place you want that to happen.

heres a test, find a tree or light pole, and slowly put your bumper next to it, and hold it, while you give it some gas IN FIRST GEAR, and let the clutch pedal out, if the engine dies right away, before you let the pedal all the way out, you got some time left in the clutch, if when you are almost all the way off of letting of the clutch pedal out and the engine is slowly chugging away, then you might get stranded some where desolate, dark and undeserving.

If it slips in your upper gears, or can't change gears with it pushed in all the way are 2.

its either hard or impossible to get into a gear.

When the car will not move any more you will know.