If you want to ascertain your own Jewish ancestry, or that of someone else, you can find clues by researching the last name. Although a typical Jewish last name does not necessarily indicate that the person is Jewish, it provides a starting point for further research. Jewish last names derive from a variety of sources, including family lineage, country of origin and the country's language. The Jewish community today divides between Ashkenazi and Sephardi Jews (with small populations of others who do not belong to either community) and last names in each community differ.

Ask whether the family has a tradition of belonging to a Cohen or Levi (priestly) family. The names Cohen and Levi almost always indicate Jewish ancestry, as do other last names that derive from these families such as Katz, Asoulin, Kahan, Kaplan and Kagan.

Look at the root of the name. Some Jewish last names derive from a Hebrew root. The Jewish name "Rappeport" comes from the profession and location of the first person with that name, a doctor ("rofeh" in Hebrew) de Puerto (the town in Italy where he lived). "Hyams" comes from the Hebrew word "Chaim," meaning "life."

Review Spanish and Portuguese last names. Some Jewish families converted to Christianity during the Inquisition, and people still associate those names with those of "Marrano," or forced converts. Some descendants of these families have returned to Judaism. Names of possible Marranos include Delgado, Ayala, Gomez, Nunes, Febos and Henriques, among others.

Research the name's meaning or whether it indicates a geographical location. When the Austrian Empire began to require Jews to adopt last names at the end of the 18th century, many Jews took names that reflected their towns of origin, a characteristic or their profession. The name "Sandler" indicated a shoemaker, "Klein" meant "small" in German, and the name "Berlin" often indicated that the person came from that city.

Note the word "son" at the end of a name. The Hebrew word "Ben" means "son of." Many Jews in Europe adopted last names that indicated their father's name, such as Abramson, Isaacson and Jacobson. Sephardic Jews used the Hebrew "Ben" even while living in Mediterranean, African or Asian countries. Examples include Ben-Avraham, Ben-Yitzhak or Ben-Ya'akov. Israel's first prime minister, David Ben Gurion, translated his last name as "David, Son of Gurion."