In this sentence error question, which part contains the grammatical error? "Karnataka receives most of its annual rainfall during the monsoon, (1) whereas Tamil Nadu does not get much then (2) and it has to wait still the advent of northeast monsoon. (3) No error (4)"

Introduction / Context:
Error detection questions test your ability to spot grammatical or usage mistakes in different parts of a sentence. The example given discusses rainfall patterns in Karnataka and Tamil Nadu and divides the sentence into three numbered segments, with a fourth option indicating no error. Your task is to identify which specific part contains the error. Such questions are common in English sections of competitive exams and require careful reading of prepositions, conjunctions and phrase patterns.

Given Data / Assumptions:

• Part (1): "Karnataka receives most of its annual rainfall during the monsoon,"
• Part (2): "whereas Tamil Nadu does not get much then"
• Part (3): "and it has to wait still the advent of northeast monsoon."
• Part (4): "No error"
• We assume standard Indian English usage, but with grammatically correct conjunctions and prepositions.

Concept / Approach:
The sentence compares rainfall patterns between two Indian states. Parts (1) and (2) are largely correct: Karnataka receives rainfall during the monsoon, whereas Tamil Nadu does not get much rainfall at that time. The problem appears in part (3), which uses the phrase "wait still the advent of northeast monsoon." In correct English, the expression should be "wait till the advent of the northeast monsoon" or "wait until the advent of the northeast monsoon." The preposition still is incorrect here; the correct word is till or until, and we also usually include the article the before northeast monsoon. Therefore, the error lies in part (3).

Step-by-Step Solution:
Step 1: Examine part (1): "Karnataka receives most of its annual rainfall during the monsoon," which is grammatically correct and makes sense.Step 2: Examine part (2): "whereas Tamil Nadu does not get much then." The word whereas correctly introduces contrast, and then refers to that time period, so this part is acceptable.Step 3: Examine part (3): "and it has to wait still the advent of northeast monsoon." The phrase "wait still the advent" sounds incorrect; the usual expression is "wait till the advent" or "wait until the advent."Step 4: Note that still is an adverb meaning "up to this time" or "nevertheless," not a preposition meaning "up to." The preposition we need to show waiting up to a point in time is till or until.Step 5: Also notice that we normally say "the northeast monsoon" with an article, not simply "northeast monsoon."Step 6: Conclude that the grammatical and usage error is located in part (3), so option C is correct.

Verification / Alternative check:
To verify, rewrite the sentence correctly: "Karnataka receives most of its annual rainfall during the monsoon, whereas Tamil Nadu does not get much then and it has to wait till the advent of the northeast monsoon." Now read each part again. Part (1) remains unchanged and correct. Part (2) still contrasts the rainfall pattern correctly. In the corrected version, only the phrase from part (3) has been changed, showing that this is where the original error was. Grammar references confirm that till or until are used for time up to a point, while still is an adverb, not a time preposition in this structure. This confirms option C as the right choice.

Why Other Options Are Wrong:

• Part (1) is grammatically sound: subject-verb agreement and prepositions are correct.
• Part (2) uses whereas correctly to introduce contrast and then to refer back to the time of the monsoon.
• Part (4) claims "No error," but we have clearly identified an error in part (3), so it cannot be correct.
• Option E (None) is unnecessary because the question already includes a "No error" choice.

Common Pitfalls:
A common mistake is to read quickly and accept still as a near synonym for till, especially for learners who may hear similar sounding phrases in informal speech. Another pitfall is to focus only on verb tenses and ignore prepositions and articles. In error spotting questions, small words like prepositions and articles are often where the mistake hides. To avoid these pitfalls, read each part carefully and consider whether any preposition or article seems slightly unnatural. Over time, exposure to correct English patterns will help you recognise such subtle errors more quickly.

Final Answer:
The correct answer is 3, because the phrase should be "wait till the advent of the northeast monsoon," not "wait still the advent of northeast monsoon."