Could someone help me out by explaining these two?

LEARNED and LEARNT.
As far as I know, and my Oxford dictionary agrees, they are both used for the same things, that is, they are just alternative forms. Either can be used for the simple past tense or the past participle.
So in all the following cases, you could use 'learned' or 'learnt':-

I learned my French the hard way.
I have learned to tread carefully when dealing with emotional teenagers.
If I had learned of his injuries earlier, I would not have asked him to carry the box.

My ear doesn't like using 'learnt' for things that took a little time to achieve, so to me, "I learned my French the hard way", sounds better than "I learnt my French the hard way." But I'd feel happy using 'learnt' in the third sentence above (the one about the injuries), because that learning was presumably immediate - someone told me about it and I absorbed the fact straight away.

This is my personal feeling, and I am afraid I cannot tell you if this would be a good guide for you. Certainly I would not make a rule about it.

Hope that helps!

Philip

Here is a lesson on learned and learnt.

Here's the summary:

If you're following US writing conventions, use learned.
If you're following UK writing conventions, use learnt.

If you're describing someone as educated, you must use learned.