Hello there, I'm a language expert with a keen interest in the intricacies of English grammar. Let's delve into the subtle yet significant distinction between the past and the past participle.
The past tense and past participle are two forms of a verb that are often used to express actions or states that occurred in the past. However, they serve different functions within a sentence and can have different forms depending on the verb.
Past Tense:

1. Usage: The past tense is used to describe a completed action that happened at a specific time in the past. It is often used with time expressions such as "yesterday," "last week," "ago," or in sentences that clearly set the action in the past.

2. Form: Most regular verbs form the past tense by adding -ed to the base form (e.g., talk → talked, work → worked). Irregular verbs have unique past tense forms (e.g., go → went, eat → ate).

3. Independence: The past tense can stand alone without the need for an auxiliary verb, making it independent in its expression of past actions.

4. Examples:
- She walked to the store yesterday.
- They played soccer last weekend.

Past Participle:

1. Usage: The past participle is used to form perfect tenses (e.g., present perfect, past perfect), passive voice, and as an adjective. It often indicates a completed action that has relevance to the present or a past action that occurred before another past action.

2. Form: The past participle is typically formed by adding -ed to regular verbs (e.g., talk → talked), but irregular verbs have distinct past participle forms (e.g., eat → eaten, go → gone).

3. Auxiliary Dependence: Unlike the past tense, the past participle often requires an auxiliary verb (e.g., have, has, had) to form perfect tenses.

4. Examples:
- She has walked to the store. (Present Perfect)
- The store had been closed when we arrived. (Past Perfect)
- The window was broken by a stray ball. (Passive Voice)
- Broken glass covered the floor. (Adjective)

Key Differences:
- Time Expression: The past tense is used with specific past time expressions, while the past participle can be used without explicit time references when forming perfect tenses.
- Auxiliary Verbs: The past tense does not require an auxiliary verb, whereas the past participle often does.
- Function in Sentences: The past tense functions as the main verb in a sentence, whereas the past participle often functions as a part of a verb phrase (with an auxiliary) or as an adjective.

It's important to note that some verbs, like "learn," have the same form for both the past tense and the past participle (learned/learnt), but this is not the case for all verbs.

Now, let's transition to the Chinese translation of the above explanation.

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The difference lies in how the word is put into past tense. Simple past tense verbs always have just one part. Past participle tense verbs have multiple parts and usually require an auxiliary verb, such as had, has or have. ... (For the verb --learn,-- --learned-- is both the simple past and past participle).read more >>