What is run-on sentence?

[AsadA969]

Hi,
I'm somewhat confused about run-on sentence.
He is a good student, he studies all day long. ......> run-on sentence, isn't it?
But, my question is:
if there is no comma or keeps other punctuation between 2 sentences, will these sentences be considered as run-on sentence ?
Here, are some examples given below.
He is a good student he studies all day long ....> is it run-on sentence?
He is a good student - he studies all day long ....>is it run-on sentence?
Thanks Ron...

[RonPurewal]

Hi,
I'm somewhat confused about run-on sentence.
He is a good student, he studies all day long. ......> run-on sentence, isn't it?

yes, that's incorrect.
yes, as far as i understand, this is the traditional definition of "run-on sentence".

He is a good student he studies all day long ....> is it run-on sentence?

this ^^ is also incorrect.

i'm not sure whether this one is also technically called a "run-on sentence", but there is no point in worrying about technical terms.

__

He is a good student - he studies all day long ....>is it run-on sentence?

this one, on the other hand, can be correct.

DASHES can take the place of just about ANY other piece of punctuation. (usually there needs to be some sort of reason, most often emphasis or irony. sometimes dashes just make a sentence easier to read, especially if it's a longer sentence that already has lots of commas.)
in this instance, if the dash is understood to play the role of a semicolon, the sentence works just fine.

[AsadA969]

He is a good student - he studies all day long ....>is it run-on sentence?

this one, on the other hand, can be correct.

DASHES can take the place of just about ANY other piece of punctuation. (usually there needs to be some sort of reason, most often emphasis or irony. sometimes dashes just make a sentence easier to read, especially if it's a longer sentence that already has lots of commas.)
in this instance, if the dash is understood to play the role of a semicolon, the sentence works just fine.

Ron, i am little bit confused about this types of construction. Here, is the 1st part (he is a good student) result of 2nd part (he studies all day long)? If the 1st part is result of 2nd part, then can we use DASH? I'm sorry to ask about punctuation. Actually, the use of dash in GMAT makes me confused to understand whole the sentence, sometimes.
Thanks Ron.

[RonPurewal]

has this been an issue in any actual GMAT problems?

this exam doesn't directly test punctuation, so this discussion is starting to veer off into territory that has nothing to do with the exam.

[AsadA969]

Thank you, Ron

[RonPurewal]

you're welcome.