set, sit

Generally, sit is something you do yourself, while set is something you do to something else.

The verb sit is intransitive, another of those “body-location” verbs like run and mosey. It can also have transitive definitions, as in sit yourself at the table.

The verb set is transitive and takes a direct object. Thus, you set something by putting it somewhere. (The dictionary contains scores of definitions of set as a transitive verb.) It can also have intransitive definitions, as in the sun sets in the evening.

Example: I want to sit on the end of the couch so that I can set my drink on the end table.