Yes, darkness is a noun and the indefinite article 'a' is grammatically correct. It would also be correct to use the definite article 'the', depending on how the word darkness is used. Examples:
A darkness invaded my thoughts. A darkness dominated the story.
The darkness made it difficult to read the text. The darkness of the stairwell made it necessary to take care.
Yes that's grammatically correct.
It is not a grammatically correct sentence, if that's what you mean. You should change "lie" to "lies", or to "lied", depending on what you wanted to say.
No
Darkness is the abstract noun.
No, the noun darkness is a concrete noun; darkness can be detected by the sense of sight.
It is grammatically correct to say: There is nothing wrong with this machine.It is not grammatically correct to say: Will it is be grammatically correct to say ....The correct way to write that or say that would be: Would it be grammatically correct to say....
'What a drunkard you are' is a grammatically correct English sentence.
Neither is grammatically correct.
No. Him and me is correct.
This sentence is grammatically correct.
It is grammatically correct to say , "I am in school today." This is because you are in the building, not at the building.
no
yes
no
It could depend on what it is you are trying to say, but as it is it is grammatically correct.
Grammatically correct, maybe, but idiomatically wrong. We normally say "buy it for me."
no it is not correct to say enjoy your vacations