Punctuation is not necessary in a sentence if a pair of adjacent words suggests an intentional conceptual relationship. However, when the pair suggests a relationship that is not a part of the intended communication, the writer must alert the reader, so some punctuation is necessary. When members of an adjacent pair do not suggest a plausible semantic relationship, the reader will try to associate the second word of the pair with an earlier element in the discourse. In cases where a more distant association does not exist, the reader must be prevented from looking for one by means of punctuation. The relevant factor in the choice between a comma and a period is the presence or absence of a lexically suggested relationship between nonadjacent words. If there is a lexical relationship between nonadjacent items, a comma is chosen. A period will be chosen where there are no lexical relationships between any two meanings on either side of the point at which punctuation is called for. Students whose writing is characterized by fragments and run-on sentences have difficulty in discerning lexical relationships. Consequently, remediation that concentrates on developing sentence skills such as analysis into subject and predicate has met with only mixed success. Remediation should concentrate on developing skills at the word level, heightening the students' awareness of the lexical relations implied by the meanings of individual words. (HOD)