Sentence Correction

Homer4 wrote:OA : B
Thanks for the response even I picked B but later I thought Is sounding warning grammatically correct?

• defending the entrance
  acting as sentinels and sounding a warning at the approach of danger, and
  scouting outside the cave for new food and roosting sites.

lunarpower wrote: for example, consider the following:
i spent all day napping, eating, and reading books and magazines
--> CORRECT
this sentence describes three things that i did: (1) nap, (2) eat, and (3) read books and magazines.
notice that #3 here is one activity, so this is actually the way in which the structure must be written in order to make sense.

i spent all day napping, eating, reading books, and magazines
--> INCORRECT
these are not four different things, so it makes no sense to write them as four parallel constructions.

i spent all day napping, eating, and reading books and writing songs
--> INCORRECT
these are actually four different activities, so they need to be written as a traditional list of four (a, b, c, and d). in this version, "reading books and writing songs" is written as though it were one activity; that's actually two different activities.

i spent all day napping, eating, reading books, and writing songs
--> CORRECT
four different activities, expressed correctly as a list of four separate parallel constructions.

the same basic principle is at work here.

lunarpower wrote:i received a private message about this thread.

vikram4689 wrote:Experts please comment if "A, B and C, and D and E" is correct structure for a list.

unfortunately, this is exactly the kind of analysis that is going to get you nowhere in general: you're trying to strip away all of the context and act as though a sentence is some sort of formula. in general, that kind of approach simply isn't going to work.
grammar is determined by context! if you take the context away, grammatical structures become meaningless!

in other words, what's troubling about the question you've asked here is that (it appears) you don't think it matters what words are in the spots you've designated as a, b, etc.
the specific words make all the difference in the world, because the context determines what is SUPPOSED to be parallel in the first place.

for example, consider the following:
i spent all day napping, eating, and reading books and magazines
--> CORRECT
this sentence describes three things that i did: (1) nap, (2) eat, and (3) read books and magazines.
notice that #3 here is one activity, so this is actually the way in which the structure must be written in order to make sense.

i spent all day napping, eating, reading books, and magazines
--> INCORRECT
these are not four different things, so it makes no sense to write them as four parallel constructions.

i spent all day napping, eating, and reading books and writing songs
--> INCORRECT
these are actually four different activities, so they need to be written as a traditional list of four (a, b, c, and d). in this version, "reading books and writing songs" is written as though it were one activity; that's actually two different activities.

i spent all day napping, eating, reading books, and writing songs
--> CORRECT
four different activities, expressed correctly as a list of four separate parallel constructions.

the same basic principle is at work here.