run-on sentence

[xuyinghao5656]

Hi Ron,

I don't know how to judge a sentence is run-on,

1 A is B and C is D.
2 A is B, C is D.

is the two sentence run-on?

[vicksikand]

A grammatically correct sentence should have a subject and a verb.
In case you have two main clauses(which can stand alone by themselves i.e. each clause has a subject and a verb) you cannot join the two claused with a "," - you need to have a co-ordinating conjunction(if relationship is that of equality).

A is B and C is D : Sub verb Obj co-ord conjunction Sub verb Obj (Not a run-on)
A is B, C is D. This is a comma-splice: joining two main clauses with a comma.

[ChrisB]

Hi,

Judging whether a sentence is a run on is straightforward once we understand what makes a clause an independent or main clause. By definition, an independent clause is formed by the presence of a subject verb pair. A run on sentence is a sentence that has two independent clauses that are not correctly joined by proper connecting punctuation or conjunction.

Let's look at your example below:

1 A is B and C is D.
2 A is B, C is D.

In each sentence, we have two independent clauses: "A is B," and "C is D." As such, each should be joined by a proper punctuation or conjunction.

#2 joins the two clauses by only a comma, which is insufficient on its own. The improper joining of two independent clauses with only a comma is commonly known as a comma splice.

#1 properly joins the two clauses with the conjunction "and." Please note, that it is more common and thus preferred to join the two clauses with a ", and" instead of just the and, though short sentences with two independent clauses will sometimes use just the conjunction "and."

Some GMAT problems will test you on whether you can spot the improper use of punctuations such as the semi-colon or omission of conjunctions such as and. As a takeaway, make sure you understand how each is used. We cover both in the sentence correction strategy guide. More specifically, I recommend you read over the chapters on subject verb agreement, parallelism, and connecting punctuation.

Thanks!
Chris