How do you say this in English (US)? which sentence is correct and WHY( explain too) { question is about articles}
1. A white and a black cow were grazing.
2. The white and the black cow were grazing.

Question

How do you say this in English (US)? which sentence is correct and WHY( explain too) { question is about articles}
1. A white and a black cow were grazing. 
2. The white and the black cow were grazing.

peachteas · Answer

2 is right.
The 2nd describes the object (That being the cows) that you are describing the colors of. Also if you are saying there are two cows and not one, make sure to add the S at the end so it shows you're talking about 2 separate cows

"The white and black cows were grazing"

peachteas · Answer

A is talking about a single object, You would need to add the object you are describing 
"A black and white cow was grazing"
or 
if you're describing more than one you can use The
"The white and black cows were grazing "

tiffachu · Answer

They can both be right depending on whether you are being specific or not

When you use “a”, it could mean any cow that you see
When you use “the”, it means specific cows

askingsaint · Answer

The reason why the left sentence in 14 is wrong is because there's only one article and a plural verb form. You can't refer to more than one item with "a", so "a black and white cow" can only ever refer to a single cow that is both black and white*. The sentence is wrong because "were" is used for plural subjects, not singular subjects. "a black and a white cow" means that there are two cows (each "a" indicates a different cow) and so you have a plural subject, so "were" is fine. The same goes for "the" with a singular noun ("cow") , so it's unrelated to the form of the article.

A black and white cow was grazing ✅
A black and a white cow were grazing ✅
A black and white cow were grazing ❌*
The black and white cow was grazing ✅
The black and the white cow were grazing ✅
The black and white cow were grazing ✅
The black and white cows were grazing ✅
A black and white cows were grazing ❌

*Edit: tiffachu brings up a good point that to some people, the sentence "a black and white cow were grazing" is natural and fine. I guess this is just one of those things that some speakers allow and others don't. 
I don't like this sentence and your textbook recommends you against it for the reasons I've outlined above, but it isn't true that you can NEVER omit articles in complex subjects, so I made a mistake in saying that.

askingsaint · Answer

@tiffachu there are sentences where you can omit the second article but this isn't one of them, or at least it isn't to me and it clearly isn't to the person who wrote the textbook. "A black and white cow are/were grazing" sounds bad to me in all contexts, it doesn't matter what the tense is. It may sound okay to you, which is fine, but to me it sounds incorrect and I need an article in front of the second noun.

I oversimplified my answer to ignore the situations where you can omit the following articles, which is my fault and I shouldn't have done that. You're correct that it is OFTEN more natural to omit following articles in a complex subject, but my point still stands that it is unnatural to do so HERE. Again, if you see nothing wrong with "a black and white cow are grazing", that's perfectly fine and I'm not going to tell you that you're wrong, people can find different things acceptable and unacceptable, but to me and to answer the question that this person had about what's written in their textbook, the reason why "a black and white cow are grazing" is incorrect is because the second article has been omitted.

tiffachu · Answer

Question 14 and 15 are bad examples to teach the use of “a” because it could mean two things:
1. Describing one cow that has two colours (black and white)
Or
2. Describing two cows (one black one white)

In question 14, they meant to describe one cow that was black and white so the verb would be “was” OR you could add an “a” to make it plural

However, it’s natural to omit the second “a” for the second subject so seeing that sentence have “were grazing”, one could assume that they were talking about two cows since the verb is plural

tiffachu · Answer

@askingsaint yeah, sorry i misunderstood the question cause I didn’t think of it saying that one cow was both black and white, didn’t notice till after a while

Jared_Hemmila · Answer

Depends on if you were talking about one cow that is black and white or one cow that is black and one cow that is white.

Assuming you were talking about two cows, one that is white and one that is black, #1 is correct. #2 is incorrect because “cow” does not agree with “were”.

If you changed #2 to “cows”, it would be technically correct, but the meaning is different than #1.

#1 means any cows, but #2 is talking about two specific cows that you already know of.

Alexsn · Answer

tiffachu's first answer is correct for the original question: both sentences could be correct, depending on whether you are talking about any two cows, or two specific cows.

askingsaint's first answer is correct for the example (14) in the book.

They are slightly different issues.

In informal conversation, we tend to omit some words -- articles and prepositions that most people would know should be there -- but in "correct" writing, if you are talking about two cows, the second "a" has to be there.

How do you say this in English (US)? which sentence is correct and WHY( explain too) { question is about articles}1. A white and a black cow were grazing. 2. The white and the black cow were grazing. See a translation

2 is right.The 2nd describes the object (That being the cows) that you are describing the colors of. Also if you are saying there are two cows and not one, make sure to add the S at the end so it shows you're talking about 2 separate cows"The white and black cows were grazing"

A is talking about a single object, You would need to add the object you are describing "A black and white cow was grazing"or if you're describing more than one you can use The"The white and black cows were grazing "

They can both be right depending on whether you are being specific or notWhen you use “a”, it could mean any cow that you seeWhen you use “the”, it means specific cows

@askingsaint yeah, sorry i misunderstood the question cause I didn’t think of it saying that one cow was both black and white, didn’t notice till after a while

How do you say this in English (US)? which sentence is correct and WHY( explain too) { question is about articles}
1. A white and a black cow were grazing.
2. The white and the black cow were grazing.

See a translation

2 is right.
The 2nd describes the object (That being the cows) that you are describing the colors of. Also if you are saying there are two cows and not one, make sure to add the S at the end so it shows you're talking about 2 separate cows

"The white and black cows were grazing"

A is talking about a single object, You would need to add the object you are describing
"A black and white cow was grazing"
or
if you're describing more than one you can use The
"The white and black cows were grazing "

They can both be right depending on whether you are being specific or not

When you use “a”, it could mean any cow that you see
When you use “the”, it means specific cows