What are the characteristics of the present perfect tense

The sign of the present perfect tense usually has the following characteristics when translated in Chinese: The present perfect tense indicates that an action has taken place in the past and continues until now. It is usually used to describe an action that started at a certain point in time and continues for a period of time. For example: - I've eaten three meals a day. - He had finished all his homework and had been reviewing for a week. The present perfect tense usually uses the auxiliary verb "already" or "finished" to emphasize that the action was completed at a certain point in the past. The present perfect tense is usually used when the subject is in the third person singular to indicate that the subject has already completed an action that has lasted until now. For example: - Little Ming had already walked for an hour. - The bird had been flying for a long time. The present perfect tense can also be used to express an evaluation of a past event or action, or an evaluation that continues to the present. For example: - This sport has been going on for five years, but I still like it very much. - He was already married but had been single until now. In short, the present perfect tense indicates that the action has continued until now. Translated in Chinese, it has auxiliary verbs such as "already" or "completed" and is usually used to describe the action of the third person singular subject.