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.
The past perfect tense of shake is had shaken.
There is no verb in the past perfect tense in that sentence. The past perfect tense of stop is had stopped. Stopped is the past tense.
"Shook" is the past tense of the verb, "to shake".
Existed is the past tense. The past perfect tense is had existed.
He had lied about his whereabouts to the police.
The past perfect tense of shake is had shaken.
shook The present perfect tense is "I have shaken".
The past continuous is 'I was shaking'. The past perfect is 'I had shaken'. The past perfect continuous is 'I had been shaking'
"had shaken" is the past perfect tense of shake.
There is no verb in the past perfect tense in that sentence. The past perfect tense of stop is had stopped. Stopped is the past tense.
The past tense of shake is shook, not shaken.
"Shook" is the past tense of the verb, "to shake".
The verb in the sentence is 'are doing,' so the past perfect tense would be 'have done.'
"shook hands" is the past tense of "shake hands".
There are two verbs in this sentence have borrowed = present perfect was = past
Existed is the past tense. The past perfect tense is had existed.
He had written a letter.