In the sentence below, select the part that contains an error: I am not familiar with (A) all the important places in this town (B) although I had been living here for two years. (C) No Error (D)

Introduction / Context:
This error spotting question tests the correct use of verb tenses when describing a situation that began in the past and continues up to the present. The speaker talks about living in a town for two years up to now, yet not being familiar with all the important places. The tense used in the subordinate clause must reflect this ongoing situation.

Given Data / Assumptions:

Sentence parts: (A) I am not familiar with, (B) all the important places in this town, (C) although I had been living here for two years, (D) No Error.

"I am not familiar" is present tense and refers to the speaker's current state.

"Had been living" is past perfect continuous, which suggests an action completed before another past reference point.

The phrase "for two years" shows the duration of residence.

Concept / Approach:

When an action started in the past and is still continuing up to the present, English normally uses the present perfect continuous tense, such as "have been living".

The past perfect continuous "had been living" is used when both the action and its reference point are in the past.

Since the main clause is in present tense, the clause about living in the town should also connect to the present with "have been living".

Step-by-Step Solution:
Step 1: Note that part A says "I am not familiar", clearly indicating that the speaker is talking about the present. Step 2: Part B, "all the important places in this town", expands this present state and is correct. Step 3: Part C, "although I had been living here for two years", uses past perfect continuous tense. Step 4: Past perfect continuous is inappropriate because there is no past reference point such as "before I moved away". The speaker is still living in the town. Step 5: The correct tense should be present perfect continuous: "although I have been living here for two years". Step 6: Thus, part C is the segment that contains the error.

Verification / Alternative check:
A corrected version of the sentence would read: "I am not familiar with all the important places in this town although I have been living here for two years." This properly connects the duration of living in the town with the present situation described in part A. Using "had been living" would only be correct if the entire sentence referred to a time in the past, which it does not.

Why Other Options Are Wrong:
Option a is wrong because "I am not familiar with" is a correct way to express lack of familiarity. Option b is wrong because "all the important places in this town" is a grammatically accurate object phrase. Option d is wrong because we have clearly identified an error in part C, so we cannot select "No Error".

Common Pitfalls:
Students sometimes overuse the past perfect tense, thinking it sounds more advanced, even when it does not fit the time reference. Another common mistake is ignoring the tense of the main clause when choosing the tense for the subordinate clause. To avoid such errors, learners should remember that present perfect or present perfect continuous links past actions with the present, while past perfect is reserved for earlier past actions relative to another past event.

Final Answer:
The correct answer is: C.