passive infinitive (grammar)

Glossary of Grammatical and Rhetorical Terms

passive infinitives in grammar
This sentence contains both an active infinitive phrase ("to catch the wind") and a passive infinitive phrase ("to be pushed by it").


In English grammar, the passive infinitive is an infinitive construction in which the agent (or performer of the action) either appears in a prepositional phrase following the verb or is not identified at all. Also called the present passive infinitive.

The passive infinitive is made up of the marker to + be + a past participle (also known as the -en form): "The case is to be decided by a judge."

See Examples and Observations below. Also see:

Examples and Observations

  • "Everybody wanted to be told over and over again the things which had happened to her."
    (Frances Hodgson Burnett, A Little Princess, 1905)

  • "The answer to that mystery was not likely to be revealed to me anytime soon."
    (Terry Phillips, Murder at the Altar. Hye Books, 2008)

  • "'Hold your tongue,' said the King, very crossly. 'I intend you to behave prettily to her. So now go and make yourself fit to be seen, as I am going to take you to visit her.'"
    (Andrew Lang, "The Little Good Mouse." The Red Fairy Book, 1890)

  • "He had come home feeling heroic, and ready to be rewarded. Playing in the big leagues again had rejuvenated him."
    (Cynthia Hartwick, Ladies With Prospects. Berkley Publishing, 2004)

  • "The foundation of imitation among us comes from the desire to be transported out of ourselves."
    (Jean-Jacques Rousseau, Emile, 1762)

  • Identifying Passive Infinitives
    "An infinitive that is derived from a passive finite verb clause will itself be passive:
    (20a.) I expect that all the calamari will be eaten before 7:00. (passive verb)

    (20b.) I expect all the calamari to be eaten before seven. (passive infinitive)
    You can verify that to be eaten is a passive infinitive in (20b) because it contains the passive marker [BE + [-en]]: be eaten. Remember that eaten is a transitive verb; in its active form, it will have a subject (an indefinite pronoun like someone or they) and a direct object (all the calamari). The active infinite version is shown in (21b).
    (21a.) I expect they will eat all the calamari before 7:00.

    (21b.) I expect them to eat all the calamari before 7:00."
    (Thomas P. Klammer, Muriel R. Schulz, and Angela Della Volpe, Analyzing English Grammar, 4th ed. Pearson Education, 2004)

  • Easy-to-Please and Eager-to-Please Constructions
    "With adjectives, passive infinitives are generally only used in PDE [present-day English] when an active infinitive may lead to ambiguity, as in the case of likely or fit, cf. you are not fit to be seen vs you are not fit to serve. Another adjective which has retained the option of using a passive infinitive is ready. Thus the well-known ambiguity of (113) can be avoided by using the variant in (114):
    (113) The lamb is ready to eat.

    (114) The lamb is ready to be eaten
    Other adjectives still allowing the passive infinitive tend to be like ready in that they can occur in both the easy-to-please construction (where the matrix subject is understood to be interpretable as the object of the infinitive) and the eager-to-please construction (where it is to be interpreted as the subject of the infinitive)."
    (Olga Fischer and Wim van der Wurff, "Syntax." A History of the English Language, ed. by Richard M. Hogg and David Denison. Cambridge University Press, 2006)