John wants Mary to stay.
"Wants" is the catenative verb here.
"To stay" is the catenative complement of "wants".
"Wants" is the head of "to stay".
"Mary" is the direct object of "wants".
"Wants" is the head of "Mary".
Therefore, "to stay" and "Mary" aren't in the same constituent. — the first conclusion
"Mary" is the subject of "to stay".
Since a verb and its subject always form the same constituent, there must be such a constituent as "Mary to stay". — the second conclusion
Could you tell me please why the conclusions contradict each other?
Also, could you explain why:
If we consider "Mary" is the head of "to stay", it contradicts the fact that "wants" is the head of "to stay".
If we consider "to stay" is the head of "Mary", it contradicts the fact that "wants" is the head of "Mary".