Can two people who CANT taste PTC have children who can?

Yes, two people who cannot taste PTC (phenylthiocarbamide) can have children who can taste it. This is because the ability to taste PTC is a genetic trait influenced by a dominant allele. If both parents are homozygous recessive for the PTC tasting gene (tt), they will not be able to taste it, but if they carry a recessive allele (t) and a dominant one (T), there's a possibility of passing the dominant allele to their children, resulting in offspring who can taste PTC.