Comma and ，comma but

[momo32]

Dear instructors,

When we use "comma and" and "comma but" we should introduce a new subject and a new verb?
Or there are some exceptions？



THX

[RonPurewal]

Dear instructors,

When we use "comma and" and "comma but" we should introduce a new subject and a new verb?
Or there are some exceptions？



THX

If "and" or "but" connects two long things--regardless of whether those things are complete sentences--then you're likely to see a comma.

Most complete sentences are fairly long; thus, when "and"/"but" connects two complete sentences, there's usually a comma.

However, there can also be a comma + "and'/"but" between two lesser grammatical pieces, if they're unusually long:
I sealed the packages with autoclave tape to isolate their contents from the surrounding air, and placed them inside a properly labeled biohazard container.
Here, "and" is merely connecting two verbs. Without the comma, though, this sentence is almost impossible to understand in a single pass.

[RonPurewal]

MUCH MORE IMPORTANTLY—
The GMAT doesn't test punctuation, so this is a non-issue.


You do have to know that this "rule" is not actually a rule; that way, you won't run around eliminating things that aren't actually wrong.
However, you will NEVER be tested on "punctuation vs. no punctuation". Never ever ever.

[NuttapongT661]

Hello! Ron,

But the rules with semicolon and colon are still tested right?

The rules like 2 sides of semicolon have to be 2 stand alone sentences, or you have to be able to replace colon with "namely" in case the colon is introducing the list of something.

Thank you in advance!:)

[RonPurewal]

Hello! Ron,

But the rules with semicolon and colon are still tested right?

The rules like 2 sides of semicolon have to be 2 stand alone sentences, or you have to be able to replace colon with "namely" in case the colon is introducing the list of something.

Thank you in advance!:)

unlike commas, those things actually change the overall structure of a sentence. so, yes, you have to know how they work.