1) I haven't some spare pen.
The answer to this is given "some", i.e. "some" is considered to be wrong here. I think the use of "haven't" and "some" together is what makes this sentence awry. Therefore, both a) and b) should be the answer. "Haven't" should be followed by a verb, therefore the use of "some" is wrong and "some" should be preceded by a "verb", therefore the use of "haven't" is wrong?
Am I right?
2)There is a little milk in the jug.
After reading the question, I figured out that both "a" and "little" are a misfit in the sentence. The answer given is "a". It would mean that the sentence -"There is little milk in the jug" is grammatically incorrect? Is it so? Is the use of "little" in this sentence correct?