A kernel sentence is a simple construction with only one verb; it is also active and declarative. Examples are: “I wrote a letter”; “She cried.”; and “We bought a car.” This basic sentence does not contain any mood and is positive. It is termed as “kernel” since it is the basis upon which other more complex sentences are formed. For example, the sentence, “It is a red pen” is made up of two kernel sentences: “It is a pen” and “The pen is red”. The kernel sentence was first introduced by linguist Z.S. Harris in 1957.