"We know little about him."
Translation:Sappiamo poco di lui.
The website I linked at the bottom describes the difference between sapere and conoscere very well. While both mean "to know" something, it refers to different types of knowledge. Sapere is to know facts and skills whereas conoscere is to know people, places and things. I'm an english speaker married to an Italian and I have confirmed it with my husband. I hope this helps! http://robinonawire.wordpress.com/2012/01/11/difference-between-sapere-conoscere-both-mean-to-know-present-tense/