what is the conjugate acid for HSO4 - and NH3??
Remember,
The conjugate acids should have one extra proton.
The conjugate bases should have one proton less.
Hence, on this bases:
Species Conjugate acid
HSO4- H2SO4
NH3 NH4+
The species: H2O,, and NH3 can act both as Brönsted acids and bases. For each case give the corresponding conjugate acid and base.