34 · Reduced and marked

Infinitive clauses

A to-infinitival clause begins with to followed by a plain verb, as in to leave the engine. It does not carry the main tense of the sentence. The complete clause can do several jobs, including direct object after wanted and complement after too heavy.

Pronoun · headNoun phrase · subjectVerb · transitive verb · headParticle · infinitival “to” · markerVerb · transitive verb · headDeterminer · determinerNoun · headNoun phrase · direct objectVerb phrase · predicateClause · infinitival nominal clause · direct objectVerb phrase · predicateSentenceShewantedtoleavetheengine
Wanted carries the outer clause’s tense. The marked clause to leave the engine is its direct object, and leave has its own direct object, the engine.

one spelling, two structures

Watch what follows “to”

What does to introduce in each sentence?
Pronoun · headNoun phrase · subjectVerb · transitive verb · headParticle · infinitival “to” · markerVerb · transitive verb · headDeterminer · determinerNoun · headNoun phrase · direct objectVerb phrase · predicateClause · infinitival nominal clause · direct objectVerb phrase · predicateSentenceShewantedtoleavetheengine

Infinitival to marks a clause whose predicate starts with plain leave.

Pronoun · headNoun phrase · subjectVerb · intransitive verb · headPreposition · headDeterminer · determinerNoun · headNoun phrase · complementPrepositional phrase · adverbialVerb phrase · predicateSentenceShewalkedtotheengine

Prepositional to heads a phrase with the noun-phrase complement the engine.

Infinitival to is followed by a plain verb and marks a clause. Prepositional to is followed by a noun phrase and heads a prepositional phrase. Some infinitival clauses have no to, as in can leave.

Trace the lower predicate

  1. Find the plain verb after infinitival to and include the words that depend on it.
  2. Find the predicate that carries the outer clause’s tense.
  3. Ask what job the complete infinitival clause has in that outer structure.

Changing wanted to wants while leave stays plain supports the nonfinite analysis, but other nonfinite clauses behave that way too. An infinitival clause can name its own subject after for, as in for them to reach. When the subject is understood rather than spoken, as in She wanted to leave, the course does not model who is understood to do the leaving.

Ten sentences from this lesson, one decision at a time.