In this English grammar sentence improvement question, you must choose the correct determiner so that the sentence sounds natural in standard usage with a negative verb. Original sentence: I will not buy some mangoes.

Introduction / Context:
This question checks your understanding of determiners such as "some" and "any" in negative sentences. Correct use of these small but important words makes your English sound natural and accurate. The original sentence "I will not buy some mangoes" feels wrong to a native speaker, and you must select the best alternative that fixes this issue.

Given Data / Assumptions:
- Original sentence: I will not buy some mangoes.
- The verb phrase is in the future negative form "will not buy".
- The noun "mangoes" is a countable plural noun.
- We need a determiner that fits a negative statement about an indefinite quantity.

Concept / Approach:
In English, "some" is usually used in positive sentences and questions offering or requesting things, such as "I bought some mangoes" or "Would you like some tea". "Any" is typically used in negative statements and most questions, such as "I did not buy any mangoes". Therefore, with a negative verb "will not", the correct determiner with a plural countable noun is "any".

Step-by-Step Solution:
Step 1: Note that the main verb phrase is "will not buy", which is clearly negative. Step 2: Recall the rule that "any" is usual in negative sentences when talking about an indefinite quantity or number. Step 3: Look at Option C, "I will not buy any mangoes", which directly follows the rule. Step 4: Check the grammar of the other options and notice they either misuse determiners or sound unnatural. Step 5: Confirm that Option C is both grammatically correct and natural sounding.

Verification / Alternative check:
Compare example sentences: "I will buy some mangoes" (positive) versus "I will not buy any mangoes" (negative). Many grammar books present this exact contrast when explaining "some" and "any". You can also test the sentence in your mind by imagining a shop situation; the negative reply almost always uses "any", not "some", which confirms the choice.

Why Other Options Are Wrong:
Option A, "a little mangoes", is incorrect because "a little" is used with uncountable nouns like water or sugar, not with plural countable nouns. Option B, "much mangoes", is wrong because "much" is also used mainly with uncountable nouns. Option D, "No improvement", keeps the unnatural "some" in a negative sentence. Option E, "few mangoes", suggests a small number but does not fit well with "will not be buying" here, and the article "a" is missing before "few" in such a context.

Common Pitfalls:
Learners sometimes overuse "some" because it feels familiar, ignoring the negative structure. Another confusion arises between "few" and "a few", and between "little" and "a little". Remember that "any" is the safest choice with negatives and questions for both countable plurals and uncountable nouns, unless there is a special emphasis or structure.

Final Answer:
The correct and natural sentence is I will not buy any mangoes.