Completion
(1) Present Perfect ( have have / has + past participle DONE ), the action occurred in the past, has been completed, the impact or consequences of now, the action is likely to continue, time can be used as the adverbial:
already (been) and yet (yet).
- They have have already arrived in on Shanghai. They had arrived to Shanghai.
Adverbial time when already completed. When have + done configuration is now complete
- She has played soccer for 3 hours. She has played three hours of football.
The subject is third person singular, the use has + done, generally for + when the sentence is completed with a time period.
- It has not finished the homework yet. She did not finish the job.
Adverbial time when yet completed, not completed their homework from the beginning to the present, present perfect representation.
(2) Past Perfect ( HAD DONE + past participle ) indicates the sentence before the action takes place in the past, that past in the past , has been completed in the past caused some of the effects or consequences.
1. They had arrived in Shanghai. They had arrived to Shanghai. Here translation is now complete and the time above the same, so the difference between what is it? Take them have arrived to Shanghai. This sentence analysis.
When the difference between the past and now completed completed
Now completed , they've arrived in Shanghai, saying these words, the time is now , the time is represented by the first person to third-person description of the time. For example, it is: I say, "They had arrived in Shanghai with" these words, represents the time is now . And the time "they arrived in Shanghai this action" has been in the past .
Past perfect , they have arrived to Shanghai, he said this time, time is past . For example, it is: I say, "They had arrived in Shanghai with" these words, represents the time is past, that is, I have to finish this sentence of time has passed. Because time had been walking, finish each sentence, the sentence has become the past.
2. She had played soccer for 3 hours. She has played three hours of football.
3. They had not finished the work yet. They have not done.
Possible translation is not apparent when the difference between the past and the completion of completion now described by the following chart:
Exercise
- When He (has stopped) the car outside. (Stop) the use of the present perfect
The third person singular subject, has the use of auxiliary verbs.
- She（hasn’t been）to Sichuan yet.（not be）
be past participle been, yet complete when the time adverbial
- (Have) they (planned) (plan) to stay here? Use the present perfect tense.
General questions usually used auxiliaries, they subject the complex, all have have auxiliary use, past participle of the verb to be changed.