3.28 true reflexive verbs
Note that the verbs 'busy', 'content', and 'pride' are true reflexive verbs: they must be used with a reflexive pronoun.
3.29
Another small group of verbs can only take an object which refers to a person when the object is a reflexive pronoun. For example, you can 'express an opinion' and you can 'express yourself', meaning that you can put ideas into words, but you cannot 'express a person'.
Here is a list of verbs which take a reflexive pronoun as object when you refer to a person: