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Logical Subjects of Infinitives


By Gerald P. Berent, Ph.D.
Department of Research
National Technical Institute for the Deaf
Rochester Institute of Technology

An "infinitive" in English is a verb preceded by the word to, as in to study. Many English verbs can be followed by a grammatical structure that contains an infinitive and is known as an "infinitive clause." In order to produce and comprehend English correctly, students need to know how to form infinitives, when to use infinitive clauses, and, most importantly, how to interpret the "logical subject" of an infinitive. Because infinitives generally do not have explicit subjects the way other, main verbs do, users of English must infer the logical, or understood, subject of an infinitive in accordance with certain inherent properties of the structures that contain infinitives.

Research has shown that deaf students are successful in interpreting some of the structures that contain infinitives but have significant problems with other structures. Especially difficult for deaf students are those structures that are exceptions to the typical pattern for interpreting logical subjects, passive sentences containing infinitive clauses, and sentences in which the logical subject relates to an entity that does not occur within the sentence. Difficulty in the interpretation of sentences containing infinitive clauses can have a major negative impact on students' reading comprehension and therefore on academic success.

This module provides an overview of infinitive clauses and the principles guiding their interpretation, a summary of research on deaf students' abilities in interpreting sentences containing infinitives, and guided practice in identifying logical subjects and in judging the difficulty of sentences containing infinitives. The module ends with action steps for teachers for addressing their students' knowledge of infinitive structures and for supporting their continuing acquisition of this aspect of English.

Major Considerations

1. English verbs are either "finite" or "nonfinite." Finite verbs have explicit subjects and express tense (for example, studied as in The student studied.) or follow helping verbs such as can, should, and must (for example, should study as in The student should study).

2. Nonfinite verbs generally do NOT have explicit subjects. Nonfinite verbs include "infinitives" (for example, to see), "gerunds" (for example, seeing), and "participles" (for example, seeing or seen). This module focuses only on infinitives.

3. Although infinitives generally do not have explicit subjects, they always have "logical subjects." English users infer these logical subjects naturally from properties of specific language structures or from the context in which sentences containing infinitives occur.

4. Sentences containing explicit subjects followed by finite verbs are generally easier for deaf students to process than sentences containing infinitives that do not have explicit subjects.

5. Many deaf students have difficulty inferring the logical subjects of infinitives. This difficulty adversely affects reading comprehension and written expression.

6. Deaf students are more successful in interpreting logical subjects for some infinitive structures than they are for other infinitive structures. Relative difficulties are determined by differences in the inherent properties of the structures themselves.

7. Teachers need to recognize infinitive structures and to understand their properties and relative difficulties for deaf students. A basic understanding of the challenges for deaf students can improve teachers' delivery of instruction.

8. Under specific circumstances, teachers can avoid, paraphrase, or simplify reading and testing materials that contain inherently more difficult sentences containing infinitive structures. Teachers can also reinforce students' acquisition of structures containing infinitives.