Thread: учиться/выучиться/научиться

roughly учиться = to learn, выучиться = to master

Научить is the perfective of учить.
Я его учил русскому - I was teaching him Russian
Я его НАучил русскому - I taught him Russian
Он русский выучил. He has learned (already finished learning entirely) Russian.

You can use this verb with words as well.
Я сегодня 3 новые слова выучил - I mastered 3 new words today.

The ВЫ prefix is used sometimes in conjuction with the perfective to show that an action has been completely done to the very end.

For example Я сегодня целую пачку ВЫкурил - I smoked an entire pack today (IE there are no more cigarettes left at all).
or 2 литра вина ВЫпил - Drank 2 literes of wine entirely.

Hope it helps.

~DOGGYBOY~!