How do you tell the difference between under sleeping and over sleeping?!

How do you tell the difference between under sleeping and over sleeping?

Are the symptoms any different? I get irregular sleep and at times I don't know if it's because I've had too little sleep or too much. The only thing I can really tell is that I tend to feel more groggy and less physically tired when I oversleep.

5 days ago
Thing is it is usually difficult for me to fall asleep...and at times, I cannot tell if I can't fall asleep because I'm not tired, or if I'm over-tired! Same thing!

5 days ago
I understand the best way to tell is by judging the times you went to sleep/woke up but I'm talking about actual SYMPTOMS, not just knowing which.

I ask this because I often have irregular sleep patterns, i.e. one day I'll sleep for 4 hours, the next 5 hours, and the next day I'll sleep for 10, and I wake up tired but is it because I slept too much or too little since I didn't make up for the last two nights enough?

You said it right.
When you oversleep you will feel quite groggy. However this is alot better than undersleeping. If you oversleep go for a run, or find some sort of exercise to do. You will generally feel fine after this if you have overslept.
Another easy way to tell is when you go to bed the next night. If you are restless and can't sleep, you probably overslept the night before.

If you undersleep you will find yourself groggy, but more frustrated because you can't seem to concentrate on things. Your mental ability is affected a lot more if you have underslept because your brain is not functioning properly.