The ten commandments I believe cover most mortal sins but they have to be explained.For instance the 1st:I am the Lord…before Me.that might cover sins like idolitry,use and belief in magic,or astrologers and a variety of others.I’ll just name some things which could be mortal under certain circumstances.Did I miss mass or come late to mass?did I leave early?Did I do servile work on Sunday/Did I give full day’s work for a full day’s pay?Did I attempt suicide?/Did i physically harm someone/Did I dress immodestly/Did I commit perjury?masturbate,adultery,fornication or sodomy?Did I gossip,give scandal by what I said or did (especially to the young),was I the cause of anyone abandoning the Catholic Faith?Did I practice birth control or was i sterilized?Did i disrespect my parents or legitimate superiors?Did i blaspheme God or take God’s name in vain?Did i neglect my duties as husband to my wife or children?Did i give bad example,abuse drugs,drink to excess?Did I kill or steal?Did i advise anyone to have an abortion or did I hav e an abortion?Did I help or encourage others to keep stolen goods?Did I?Did i tell lies to decieve or injure others?Did i give fair wages to my employees?There are other ways to commit mortal sins but this covers quite a few.Now it depends on degree and intent for some of these to be mortal.Most often many of these woould be venial sins.