So we would like to ask a similar question about meanings. To get at the stuff meaning is made of, we start with a simple concrete idea. The described situation is the one in which the hamburger giving takes place. Tense, for example, makes reference to position in time of the described situation relative to the speech situtation. Definiteness cares only about the speech situation.
Number cares only about the described situation.
A curious fact about some of the markers has to do with agreement. But this is marked on the verb as well. The choice of were as opposed to was indicates that the giver is plural. In this case we say the verb agrees with the subject noun phrase. The categories of meaning singled out here appear to be grammatically significant.