范文：
The word "help" has two past tenses: "helped" for the simple past tense, which is used to describe an action that was completed at a specific time in the past, and "had helped" for the past perfect tense, which is used to describe an action that was completed before another past action.
For example:
I helped my friend move to a new house yesterday. (Simple past)
By the time I arrived at the party, she had helped set up the decorations. (Past perfect)
常见问答知识清单：
1. What is the past tense of help?
2. How do you form the past tense of help?
3. When do you use the simple past tense of help?
4. When do you use the past perfect tense of help?
5. Can help be used in both the simple past and past perfect tenses?
6. What is the difference between helped and had helped?
7. Can help be used in passive voice in the past tense?
8. How do you use helped in a sentence?
9. Can you provide an example of a sentence using the past perfect tense of help?
10. Is help irregular in the past tense?
详细解答：
1. What is the past tense of help?
The past tense of "help" is "helped."
2. How do you form the past tense of help?
The past tense "helped" is formed by adding the suffix "ed" to the base verb "help."
3. When do you use the simple past tense of help?
The simple past tense is used to describe an action that was completed at a specific time in the past. For example, "I helped my neighbor move the furniture last week."
4. When do you use the past perfect tense of help?
The past perfect tense is used to describe an action that was completed before another past action. For example, "By the time the doctor arrived, she had already helped the injured man."
5. Can help be used in both the simple past and past perfect tenses?
Yes, "help" can be used in both the simple past tense ("helped") and the past perfect tense ("had helped").
6. What is the difference between helped and had helped?
"Helped" is the simple past tense and indicates that the action was completed at a specific past time. "Had helped" is the past perfect tense and indicates that the action was completed before another past action.
7. Can help be used in passive voice in the past tense?
Yes, "help" can be used in the passive voice in the past tense. For example, "The furniture was helped moved by my friend."
8. How do you use helped in a sentence?
You can use "helped" in a sentence like this: "She helped me study for the exam."
9. Can you provide an example of a sentence using the past perfect tense of help?
An example is: "By the time the meeting started, he had helped organize the event."
10. Is help irregular in the past tense?
No, "help" is considered regular in the past tense. It follows the standard pattern of adding "ed" to form the past tense.
