Logical Subject Assigned from Outside the Sentence
In the examples considered so far, the logical subject of an infinitive is interpreted as equivalent to some explicit noun phrase (subject or object) elsewhere in the sentence. Sometimes, however, a logical subject is associated with an entity that does not occur in the same sentence. Consider this sentence:
The design team manager said § to change the design of the computer.
There is no noun phrase in this sentence that can be considered as the logical subject of to change. The design team manager cannot be interpreted as the person who is expected to do the changing. Instead, the logical subject of to change has to be someone understood within the context in which this sentence would be spoken or written. Perhaps a design team member or members are being referred to. It is a property of the verb say that allows an infinitive clause to follow it without the explicit mention of who is expected to do the action expressed by the infinitive.
Incidentally, say also allows the explicit mention of a noun phrase after for to serve as the logical subject of the infinitive, as in the following sentence:
The design team manager said for the engineer § to change the design of the computer.
Another verb that behaves like say is explain when it is followed by an infinitive clause beginning with a WH-word, as in these sentences:
The design team manager explained how § to change the design of the computer.
The design team manager explained what § to change.
In each of these sentences, the logical subject of to change must be interpreted as someone understood within the context in which such sentences would be spoken or written.