1999 Hyundai Accent car won't start

Hi, I have a 1999 accent manuel trans I've had it for over 2 years. This morning it wouldn't start it cranked over for 3 seconds then nothing I thought my foot let the clutch up a little but when I depressed it again it still didn't turn over, the battery is less than 1 1/2 years old, all my lights, radio, heater, dash light and gauges worked. This afternoon I got a push popped the clutch and it started right away so I let it run for at least an hour shut it down and it wouldn't turn over. Any ideas of what I can check?

Thanks so much for any help you can give me.
Alan