Choose the correct one.
I was tired because I ______ for a long time.

Question

Choose the correct one.
 I was tired because I ______ for a long time.

Accepted Answer

The sentence in question is: "I was tired because I ______ for a long time." The task is to fill in the blank with the correct verb form. The correct answer is Option 3: "had been working."

1. **Explanation for Option 3 (Correct Answer):**
   - The sentence is structured in the past tense, as indicated by "I was tired." This suggests that the action causing the tiredness also occurred in the past. The phrase "had been working" is in the past perfect continuous tense, which is used to describe an action that started in the past and continued up to a certain point in the past. In this context, "had been working" appropriately indicates that the speaker was engaged in work for a long duration before the point in time when they felt tired. This tense effectively links the past action of working with the past state of being tired, making it the correct choice.

2. **Explanation for why the other options are incorrect:**
   - **Option 1: "was working"**
     - "Was working" is in the past continuous tense, which describes an ongoing action in the past. However, it does not convey the sense of an action that was completed before another past action or state (being tired). It lacks the aspect of duration leading up to the point of tiredness, which is crucial in this context.
   
   - **Option 2: "have been working"**
     - "Have been working" is in the present perfect continuous tense, which is used for actions that started in the past and continue into the present or have relevance to the present. This tense is inappropriate here because the sentence is entirely set in the past. The use of "have been working" would incorrectly suggest that the working continued up to the present, which contradicts the past context of the sentence.
   
   - **Option 4: "am working"**
     - "Am working" is in the present continuous tense, indicating an action that is currently ongoing. This tense is unsuitable for the sentence because it shifts the timeframe to the present, whereas the sentence clearly describes a past situation. Using "am working" would imply that the speaker is currently working, which does not align with the past context of feeling tired.

In summary, Option 3, "had been working," is the correct choice because it accurately reflects an action that occurred over a period in the past and was completed before the speaker felt tired. The other options fail to convey this past relationship appropriately.