A complete sentence must have a subject and a verb; a sentence fragment is a sentence that doesn't have both of those. Fragments can be very short or quite long; the only qualification is that they are missing one or both of those two necessary elements. A run-on sentence is one that has more than one independent clause (i.e., more than one subject and verb) without the proper connectors (e.g., a semicolon or a conjunction with a comma.) A common type of run-on sentence on the GMAT is the comma splice, in which two independent clauses are connected with only a comma.

grockit_andrea wrote:A complete sentence must have a subject and a verb; a sentence fragment is a sentence that doesn't have both of those. Fragments can be very short or quite long; the only qualification is that they are missing one or both of those two necessary elements. A run-on sentence is one that has more than one independent clause (i.e., more than one subject and verb) without the proper connectors (e.g., a semicolon or a conjunction with a comma.) A common type of run-on sentence on the GMAT is the comma splice, in which two independent clauses are connected with only a comma.

Andrea ,

Thanks that things makes much clearer. Could you kindly give us examples of both that will help a lot. Thanks again, for the post above.

grockit_andrea wrote:A complete sentence must have a subject and a verb; a sentence fragment is a sentence that doesn't have both of those. Fragments can be very short or quite long; the only qualification is that they are missing one or both of those two necessary elements. A run-on sentence is one that has more than one independent clause (i.e., more than one subject and verb) without the proper connectors (e.g., a semicolon or a conjunction with a comma.) A common type of run-on sentence on the GMAT is the comma splice, in which two independent clauses are connected with only a comma.

Thanks Andrea.

Please share some more GMAT types examples to show these concepts.

grockit_andrea wrote:A complete sentence must have a subject and a verb; a sentence fragment is a sentence that doesn't have both of those. Fragments can be very short or quite long; the only qualification is that they are missing one or both of those two necessary elements. A run-on sentence is one that has more than one independent clause (i.e., more than one subject and verb) without the proper connectors (e.g., a semicolon or a conjunction with a comma.) A common type of run-on sentence on the GMAT is the comma splice, in which two independent clauses are connected with only a comma.

Thanks Andrea,
Could you also explain how is comma splice error different from run on sentence error?

Also if you could add eg for each of those, would be much appreciated.

Sentence Fragment 1:

Because of the boy.

This is a sentence fragment because there's no verb, and "because of the boy" sounds like a modifying phrase. You are very unlikely to encounter a fragment this short on the GMAT.

Sentence fragment 2:

Because of the boy and his interest in model trains, which he had learned about from his great-grandfather, who had also been a model train collector.

This is a sentence fragment because it's nothing but a collection of phrases, with no subject or verb. We don't know what was "because of the boy," so the first phrase doesn't have a clear subject or any kind of verb; the second phrase modifies "model trains," and the third modifies "his great-grandfather." This is the kind of fragment you will be most likely to see on the GMAT.

Run-on Sentence 1:

Because of the boy and his interest in model trains, the family vacationed in Ohio, where there was a model train museum and they visited it on the first day of their trip.

This is a run-on sentence because it has two independent clauses connected by a conjunction but no comma. You could put a period after "museum," delete "and," and capitalize "they," and you would have 2 sentences. To correctly connect those sentences, you need either a semicolon or a comma with a conjunction.

Run-on Sentence 2:

Because of the boy and his interest in model trains, the family vacationed in Ohio, where there was a model train museum, they visited it on the first day of their trip.

This is a specific kind of run-on sentence called a comma splice, where two independent clauses are connected with only a comma. Again, these phrases could be split with a period after "museum," instead of a comma.

Correct Version of this Sentence 1:

Because of the boy and his interest in model trains, the family vacationed in Ohio, where there was a model train museum; they visited it on the first day of their trip.

A semicolon is one correct way to connect two related but independent clauses into a single sentence. This is common on the GMAT.

Correct Version of this Sentence 2:

Because of the boy and his interest in model trains, the family vacationed in Ohio, where there was a model train museum, and they visited it on the first day of their trip.

A second way to correctly connect the two independent clauses is with both a comma and a conjunction.

Hope this helps clarify!