What does it mean for a control verb to semantically select its arguments?

Question

I'm attempting to better understand what a control verb is. The Wikipedia definition seems clear enough. But the definition in this other Wikipedia article, about Control, was harder for me to understand.

Here's one quote from the article whose meaning I need to learn...

"Control predicates have semantic content; they semantically select their arguments, that is, their appearance strongly influences the nature of the arguments they take.[3] In this regard, they are much different from auxiliary verbs, which lack semantic content and do not semantically select arguments."

What is meant here by "their appearance," i.e. the "appearance" of control verbs? What aspect of the "nature" of the arguments do control verbs influence? What does "semantic selection" mean in this context?

Answer 1

A verb is said to have selectional restrictions if there are certain well-defined properties that licit arguments must have. The verb massacre, for example, selects for a plural object. In semantic selection, the selected property must be semantic, and in studies on argument structure "semantic" usually means a role like agent, patient, instrument, etc., which are grammaticalized into grammatical relations such as subject, object, etc. In the Wikipedia article, what they are getting at is that the subject of the subordinate clause is either the subject or the object of the control verb.

Edit

It occurred to me that it probably means instead that the semantics of the control verb are responsible for deciding whether its subject or object is the subject of the subordinate clause.