Predictable Problems in Sentence structure 02: run-on sentences

Question: What are some problems in sentence structure that you can predict will appear in students’ writing?

Answer: the run-on sentence (also called a “comma splice”) in which two complete sentences are connected inadequately by a comma.

Solutions: period; semicolon; coordinate conjunction; subordinate conjunction.

Simplified sentence: “I saw the Phillies play, they lost as usual.” (Run-on sentence or comma splice.)
Corrected: “I saw the Phillies play. They lost as usual.” (Period.)
Corrected: “I saw the Phillies play; they lost as usual.” (Semicolon.)
Corrected: “I saw the Phillies play and they lost as usual.” (Coordinate conjunction.)
Corrected: “When I saw the Phillies play, they lost as usual.” (Subordinate conjunction)

Note: Coordinate conjunctions: “and,” “but,” “or,” “nor,” “for,” “yet,” “so.”
Subordinate conjunctions: “when…,” “after…,” “because…,” “since…,” etc.

Important variation: the use of "however," "nevertheless," etc. is one of the most frequent run-ons. “I saw the Phillies play, however, they lost as usual.” (Run-on, comma splice.)
Corrected: “I saw the Phillies play; however, they lost as usual.”
(; however,)

Simplified sentences clearly demonstrate the problem of and the solutions to run-on sentences. However, the problem will not be as obvious when older students and adults are using long sentences. Here are some longer run-on, comma splice sentences from Warriner’s English Grammar and Composition, 1986:

Run-on: “Ynes Mexia, the botanical explorer, discovered rare tropical plants on her expeditions to Mexico and South America, these discoveries were of great value to science.” p. 277.

Corrected: “Ynes Mexia, the botanical explorer, discovered rare tropical plants on her expeditions to Mexico and South America. These discoveries were of great value to science.” (period)

Run-on: “The astounding scientific developments of one generation are accepted commonplaces in the next generation, the computer and the cassette recorder, for instance, are taken for granted by everyone today.” p. 278.

Corrected: “The astounding scientific developments of one generation are accepted commonplaces in the next generation; the computer and the cassette recorder, for instance, are taken for granted by everyone today.”(semicolon)

If run-on sentences are among your habitual problems, type "run-on sentences" in Google. and click "Go." The last time I checked, Google had 1,720,000 Web sites dealing with run-on sentences, many of them exercises, with some interesting presentations explaining the problem.

All the best. RayS.