# How can I name compounds with multiple functional groups?

The idea is that the same compound cannot, or must not, have two (or more) different names. If there are more functional groups, e.g. a $- O H$ and a $- C O O H$ as in lactic acid, the naming is defined as 2-hydroxypropanoic acid, because the acid part has preference as a suffix. If this preference didn't exist, other names would be possible (work that out for yourself).