Past pefect (Plusquamperfekt) is formed by combining the past participle with the simple past tense form of the auxiliary haben or sein.
Ich war im Konzert gewesen. - I had been to the concert.
Ich hatte die Schlüssel vergessen. - I had forgotten the keyes.
The thing is to know if verb (or context) require habenor sein.
"Had written" is the past perfect tense of "write".
Wrote is the simple past; had written is the past perfect.
Past perfect is formed with - had + past participle.The past participle of write is written so past perfect of the verb write is:had writtenHe had written to me once but after that I lost contact with him.
The conclusions are contained in the agency's latest report.This sentence is a passive sentence, a present simple passive sentence. The verb phrase is - are contained = be verb + past participle.Past perfect passive sentence:The conclusions had been contained in the agency's latest report.
Past perfect is formed with - had + past participle.In the sentence - I had some dates - had is the past form of have and had is also the past participle of haveSo your sentence in past perfect would be - I had had some dates.In present perfect - I have had some dates.Using another verb (not have) - I had eatensome dates. I had been to London.
The past perfect tense is 'I had written'.The present perfect tense is 'I/you/we/they have written. He/she/it has written.
He had lied about his whereabouts to the police.
You can't make a past perfect sentence with the word shake.The past participle form of the verb is used in past perfect. The past participle of shake is shaken.He had shaken his fist at me.
You should have written. This is present perfect so the past participle of the verb write should be used - written.
Past perfect is formed this way - had + past participle.Because cash is a regular verb the past participle of cash is cashed.So a past perfect sentence would be: He had cashed the cheque.
To create the past perfect, you need had + a past participle.The verb arrive in the past perfect = had arrived.The verb eat in the past perfect = had eaten.Note that it's always had for first, second, and third person singular and plural when creating the past perfect.
The past perfect is had written.The present perfect is has/have written.The future perfect is will have written.