Model Answer
0 min readIntroduction
The question presents a simple sentence requiring correction based on grammatical principles. The core issue revolves around the correct application of tenses to express a relationship that began in the past (January) and continues to the present. Understanding the nuances between 'know' (present indefinite), 'have known' (present perfect), and 'have been knowing' (present perfect continuous) is crucial for accurate sentence construction. The task is to identify the incorrect tense and provide the grammatically sound alternative.
They have known each other since January.
Explanation of the Error
The original sentence, "They know each other since January," is incorrect because the present indefinite tense ("know") is not suitable for an action that started in the past and continues to the present. The phrase "since January" indicates a duration from a specific point in the past, necessitating the use of the present perfect or present perfect continuous tense.
Why Present Perfect is Correct
The present perfect tense ("have known") is used to describe an action that started in the past and continues to have relevance in the present. It emphasizes the experience or the state resulting from the past action. In this case, the fact that they *have* known each other since January is relevant to their current relationship.
Why Present Perfect Continuous is also acceptable (though less common in this context)
While "They have been knowing each other since January" is grammatically correct, it sounds less natural. The present perfect continuous emphasizes the *duration* of the action. It's more commonly used when focusing on the ongoing nature of the relationship, but the present perfect is more standard in this context.
Alternative Corrected Sentence (Less Common)
They have been knowing each other since January.
Grammatical Rules Applied
- Present Indefinite Tense: Used for habitual actions, general truths, and facts.
- Present Perfect Tense: Used for actions completed at an indefinite time in the past, or actions that started in the past and continue to the present. (Subject + have/has + past participle)
- Present Perfect Continuous Tense: Used for actions that started in the past and are still continuing. (Subject + have/has + been + verb-ing)
Conclusion
The corrected sentence, "They have known each other since January," accurately reflects the ongoing nature of their acquaintance, starting from January and continuing to the present. The key lies in recognizing the temporal context provided by "since January" and applying the appropriate tense – the present perfect – to convey the intended meaning. While the present perfect continuous is also grammatically valid, the present perfect is the more natural and commonly used form in this scenario.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.