I learned how to read and write Hebrew from going to Hebrew school twice a week after school.   I did not learn how to speak it conversationally until age 21.  I took a few classes in college and I was able to pick it up quickly because I had so many years of practicing the alphabet.  I continued my Hebrew language education in ulpan at the JCC of Manhattan (intensive courses).  I had a private tutor for a while too.  I use a Hebrew keyboard on my computer and iPhone sometimes to force me to keep learning and to communicate in Hebrew to my Hebrew-speaking friends and family.