 Matters get more complicated, and more controversial, as we extend this sort of theory of reference to cover more and more of the types of expressions we find in natural languages like English. (For an introduction, see Heim and Kratzer (1998).) But the above is enough to give a rough idea of how one might proceed. For example, some predicates, like “loves” combine with two names to form a sentence, rather than one. So the reference of two-place predicates of this sort must be something which combines with a pair of objects to determine a truth-value—perhaps, that function from ordered pairs of objects to truth-values which returns the truth-value “true” when given as input a pair of objects whose first member loves the second member, and “false” otherwise.