**Use your flowchart, periodic table, and polyatomic ion sheet to do this.
If your formula starts with a metal (and only has one oxidation number), there is nothing special to do.
If your formula starts with a metal with more one oxidation number (transition metal), you will need a roman numeral. You may have to use oxidation numbers backwards to figure that out.
If your formula starts with an nonmetal, you will need prefixes.
copper (II) sulfide
copper (II) sulfate
magnesium sulfite
lithium sulfide
Ca3P2
Na3PO4
CrPO3
K3N
Ca(NO3)2
Al(NO2)3
SO3
BF3