A double is a word that performs the functions of two parts of speech simultaneously. There are various ways for this to occur, so do not think we offer an exhaustive list of doubles.

Six Common Doubles

To determine the primary role of any word in a sentence, you should ask yourself if the word names (nouns), describes (adjectives), or has another specific task. The task of the word within a sentence is its syntactical function. There are six common doubles in English:

  • Possessive nouns act as nouns and adjectives.
  • Possessive pronouns act as nouns and adjectives.
  • Adverbial nouns act like adverbs and nouns.
  • Participles act as verbs and adjectives.
  • Gerunds act as verbs and nouns.
  • Infinitives act as verbs and nouns; verbs and adjectives; or verbs and adverbs.

In addition, indefinite and demonstrative pronouns can act as adjectives when appearing next to nouns.

Possessive Nouns

A possessive noun can be a proper or common noun, punctuated to indicate ownership. Ownership describes another noun or pronoun, so the word is acting as an adjective.

Alice’s new book is selling well.

The dog’s owner is cruel.

Possessive Pronouns

A possessive pronoun indicates ownership of a noun or pronoun. As with possessive nouns, ownership describes another noun or pronoun.

I would to meet her family.

Where is its owner?

Adverbial Nouns

An adverbial noun acts as an adverb by indicating distance, time, weight, or value. If a noun indicates how much or to what degree an action or state exists, the noun is acting as an adverb. Adverbial nouns are sometimes called adverbial objectives.

The large cat might weigh twenty pounds.

He will attend the meeting next month.

The noun phrase twenty pounds answers the adverbial question how much? The words twenty and pounds are nouns, relying on each other for meaning. While month is a conceptual noun, it can also indicate the time for an event.

Remember that some nouns can be converted to adverbs by adding a suffix. If a group meets monthly we know it meets every month. If a noun has an adverbial form, the noun can be an adverbial noun.


A participle is a conjugated verb acting as an adjective. Before identifying participles, locate the simple predicate verb in a sentence. After you locate other verbs, determine if they modify nouns.

We visited a lake known for its clear water.

The verb known follows and modifies the noun lake. The participle introduces a description, which participles often do.


A gerund is a verb conjugated with the ending -ing. Gerunds act as nouns and verbs. Identifying another verb as the simple predicate allows you to recognize gerunds acting as nouns.

Elizabeth goes running every morning.

Elizabeth’s running is a noun and a verb. In the example, running is a conceptual noun for a hobby or special interest.


The infinitive form of a verb is the verb preceded by to. Simple examples are to be and to walk. Infinitives can act as verbs, nouns, adjectives, and adverbs. Analyze infinitives carefully before assuming one is acting like a noun.

Roland enjoys planning stories to write more than writing them.

To plan is easier than to do.


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Writer: C. S. Wyatt
Updated: 08-Mar-2017
Editor: S. D. Schnelbach