To name oxyacids, you must first be able to recognize them by the general formula HaXbOc, with X representing an element other than hydrogen or oxygen.
It will also be useful for you to know the names of the polyatomic oxyanions, because many oxyacid names are derived from them. If enough H+ ions are added to a (root)ate polyatomic ion to completely neutralize its charge, the (root)ic acid is formed. See below.
If one H+ ion is added to nitrate, NO3−, nitric acid, HNO3, is formed.
If two H+ ions are added to sulfate, SO42−, sulfuric acid, H2SO4, is formed.
If three H+ ions are added to phosphate, PO43−, phosphoric acid, H3PO3, is formed.
Notice that the whole name for sulfur, not just the root, sulf‑, is found in the name sulfuric acid. Similarly, although the usual root for phosphorus is phosph-, the root phosphor‑ is used for phosphorus-containing oxyacids, as in the name phosphoric acid.
NO3− is nitrate, and HNO3 is nitric acid.
C2H3O2− is acetate, and HC2H3O2 is acetic acid.
SO42− is sulfate, and H2SO4 is sulfuric acid.
CO32− is carbonate, and H2CO3 is carbonic acid.
PO43− is phosphate, and H3PO4 is phosphoric acid.