Normally, when you start learning Japanese, you are first thought of は (ha/wa) as a topic marker, focusing one’s attention on the part of the sentence that follows the particle. When most of the time it is used precisely in this purpose, you may also encounter it in sentences where it shows the contrast of the phrase or the word with something else. For example:
I read newspapers, but I don’t read books.
I went to Tokyo, but I didn’t go to Kyoto.
Men should have courage, women should have charm. (Japanese proverb)
In some cases, the contrast may also be implicit as can be seen in the following examples:
I don’t drink beer [, but there may be other beverages that I’ll gladly drink with you].
In this case, you are implying that you are interested in a drink—just not beer. This is something that wouldn’t come through if you would have used the を (wo/o) particle instead.
I hope that this short article could kindle your interest in particles—one of the most interesting, but at the same time one of the most difficult, aspects of Japanese grammar. If you know of any other interesting or uncommon use of the は particle, please leave a comment below! Oh, and by the way, if you haven’t tried it yet, go play the NihongoUp Game and learn particles the fun way!