Error Spotting (Grammar) — choose the part that contains a grammatical error. If the sentence is correct, choose ‘‘No error.’’ Complete sentence: We have been living in this house since two years.

Introduction / Context:
This checks correct use of ‘‘since’’ and ‘‘for.’’ ‘‘Since’’ takes a point in time; ‘‘for’’ takes a duration.

Given Data / Assumptions:

• ‘‘two years’’ is a duration, not a starting point.
• Present perfect progressive is otherwise correct for a continuing action.

Concept / Approach:
Use ‘‘for + duration’’ and ‘‘since + starting time.’’ Thus ‘‘for two years’’ is required.

Step-by-Step Solution:
Spot preposition mismatch: ‘‘since two years’’.Replace with ‘‘for two years.’’Corrected sentence: ‘‘We have been living in this house for two years.’’

Verification / Alternative check:
If there were a starting year (e.g., ‘‘since 2023’’), ‘‘since’’ would be correct. With a bare duration, ‘‘for’’ is mandatory.

Why Other Options Are Wrong:

• ‘‘We’’ — fine.
• ‘‘have been living’’ — correct aspect for ongoing action.
• ‘‘in this house’’ — correct prepositional phrase.
• ‘‘No error.’’ — incorrect because part D is wrong.

Common Pitfalls:
Confusing ‘‘since’’ and ‘‘for’’ due to L1 transfer or memorized chunks.

Final Answer:
since two years.