Kernel Sentence Definition and Examples

Glossary of Grammatical and Rhetorical Terms

Examples of kernel sentences in English.

In transformational grammar, a kernel sentence is a simple declarative construction with only one verb. A kernel sentence is always active and affirmative. Also known as a basic sentence or a kernel.

The concept of the kernel sentence was introduced in 1957 by linguist Z.S. Harris and featured in the early work of linguist Noam Chomsky.

Examples and Observations

  • "A kernel sentence does not contain any optional expression and is simple in the sense that it is unmarked in mood, therefore, it is indicative. It is also unmarked in voice, therefore, it is active rather than passive. And, finally, it is unmarked in polarity, therefore, it is a positive rather than a negative sentence. An example of a kernel sentence is 'The man opened the door,' and an example of a non-kernel sentence is 'The man did not open the door.'"
    (Shefali Moitra, "Generative Grammar and Logical Form." Logic Identity and Consistency, ed. by Pranab Kumar Sen. Allied Publishers, 1998)
  • "Even a sentence with an adjective, gerund or infinitive is not a kernel sentence.
    (i) This is a black cow is made of two kernel sentences
    This is a cow and The cow is black.
    (ii) I saw them crossing the river is made of I saw them and They were crossing the river,
    (iii) I want to go is made of I want and I go."
    (M.P. Sinha, Modern Linguistics. Atlantic Publishers, 2005)

Chomsky on Kernel Sentences

"[E]very sentence of the language will either belong to the kernel or will be derived from the strings underlying one or more kernel sentences by a sequence of one or more transformations. . . .

"[I]n order to understand a sentence it is necessary to know the kernel sentences from which it originates (more precisely, the terminal strings underlying these kernel sentences) and the phrase structure of each of these elementary components, as well as the transformational history of development of the given sentence from those kernel sentences. The general problem of analyzing the process 'understanding' is thus reduced, in a sense, to the problem of explaining how kernel sentences are understood, these being considered the basic 'content elements' from which the usual, more complex sentences of real life are formed by transformational development." (Noam Chomsky, Syntactic Structures, 1957; rev. ed., Walter de Gruyter, 2002)


"A kernel clause which is both a sentence and a simple sentence, like His engine has stopped or The police have impounded his car, is a kernel sentence. Within this model, the construction of any other sentence, or any other sentence that consists of clauses, will be reduced to that of kernel sentences wherever possible. Thus the following:

The police have impounded the car which he left outside the stadium

is a kernel clause, with transforms Have the police impounded the car which he left outside the stadium? and so on. It is not a kernel sentence, as it is not simple. But the relative clause, which he left outside the stadium, is a transform of the kernel sentences He left a car outside the stadium, He left the car outside the stadium, He left a bicycle outside the stadium, and so on. When this modifying clause is set aside, the remainder of the main clause, The police have impounded the car, is itself a kernel sentence." (P. H. Matthews, Syntax. Cambridge University Press, 1981)