Martha Speaks is a children's animated television series based on the 1992 children's book of the same name by Susan Meddaugh.[3] The series is produced by WGBH-TV in Boston, along with Canadian animation studios DHX Media Vancouver and Oasis Animation. It premiered on September 1, 2008 and ended on November 18, 2014, lasting for six years. Some episodes of this television series were available for limited theatrical release on January 3, 2009.[4] The show focuses mainly on synonyms and vocabulary, with each episode featuring an underlying theme illustrated with (usually informal) keywords. The show also occasionally focuses on introducing children ages 4-7 to different concepts of science, history, astronomy, and other learning concepts, such as the Spanish language, through passing mentions.[a] The second season began airing on September 14, 2009. The third season of Martha Speaks premiered on PBS Kids on October 11, 2010,[5] and the fourth season began airing on February 20, 2012.[6] The fifth season premiered on June 24, 2013. The sixth and final season premiered on March 31, 2014.[7] Since the series' conclusion, reruns aired on PBS Kids.