How to tell whether something is a primary source or a secondary source?

A primary source is a source that comes directly from what you are trying to research. For example, a recording of an interview is a primary source, whereas a secondary source would be an essay written about the interview.

Usually, primary sources are tellings of an event from the time that it happened. They are usually in first person and factual e. g. diaries, journals, photographs, records, etc.

Secondary sources usually take a look and analyze primary sources. They might also be a second hand explanation of an event and can be more interpretive than factual e. g. biographies, newspapers, analytical papers.

Hope you understand.

:D