What are the functions of object infinitive clauses? Provide examples.

The functions of object infinitive clauses are to act as the direct object of a verb or a preposition. They provide additional information about the action or state expressed by the main verb. Here are some examples:

1. Direct Object:
- She wants to learn how to play the piano. (The object infinitive clause "to learn how to play the piano" acts as the direct object of the verb "wants.")

2. Prepositional Object:
- He is excited about going on vacation. (The object infinitive clause "going on vacation" acts as the object of the preposition "about.")

3. Subject Complement:
- Her dream is to become a doctor. (The object infinitive clause "to become a doctor" acts as the subject complement, providing additional information about the subject "her dream.")

4. Adjective Complement:
- The decision was difficult to make. (The object infinitive clause "to make" acts as the adjective complement, describing the difficulty of the decision.)

5. Expletive Construction:
- It is important to exercise regularly. (The object infinitive clause "to exercise regularly" serves as an expletive construction, where "it" functions as a placeholder subject.)

6. Verb Complement:
- They expect him to arrive on time. (The object infinitive clause "to arrive on time" acts as the complement of the verb "expect," indicating what they expect him to do.)

These examples demonstrate the various functions of object infinitive clauses in providing additional information, acting as direct objects, prepositional objects, subject complements, adjective complements, expletive constructions, or verb complements.