英文 現在完成式 過去完成式

Have you ever been to Hong Kong?

It asked you if you have had the "experience" of being in Hong Kong.

Have you ever been to Hong Kong? = 你曾經有去過香港?

這句使用現在完成式, 時間是指你從出生開始, 直到現在, 你有沒有去過香港?
現在完成式是動作在過去發生, 一直持續到現在. 是與現在有關聯

其他例子:
He has never eaten a snail.

如果用過去完成式, Had you ever been to Hong Kong?
時間界限是從出生開始直到過去某一點時間, 這個某一點不會現在, “去過香港”終止在過去某一時間

兩者不同是:
現在完成式表現現時這一時間點之前發生動作
過去完成式表現過去某一時間點之前發生動作, 過去的過去
使用過去完成式需要過去某一時間為前提, 通常用時間狀語,

By the age of 21, had you been to Hong Kong? (你現在已經不止 21歲)
不包括21歲以上這段時間

時間狀語可由雙句擔任, 並且用 past simple tense

Had you been to Hong Kong before you came back America last year?
----- past perfect……., ------ past simple …………..

其他例子:
The train had left when he arrived at the station.

Have you ever been to Hong Kong up to now?
Had you ever been to Hong Kong when you arrived last week?

現在完成式 Present Perfect 係指 recent past with indefinite adverbs of time 最近過去而時間副詞没有指定的

過去完成式 Past Perfect 係指 for the first of two past actions 兩個過去式的動作的第一個

因為現在完成式係 （ have /has + pp ）

表示過去到目前為止已有的經驗或已經完成的事.

而過去完成式 （ had +pp ）

表示在過去某件事發生前就已經完成的動作或經驗, 所以一定要和過去式合用.

Had you ever been to Hong Kong? 唔係係某件事發生前就已經完成的動作

Past perfect tense cannot be used here.---Technically, it is the form of a verb that shows that the action described by the verb was completed before a particular time in the past, formed in English with "had" and a past participle had learnt--past perfect tense--eg:-He had learnt Chinese before he came to Hong Kong.
ever=adverb=used mostly in questions, negatives, comparisions, and sentences with (Have) at any time.
eg"Do you ever go to HK?"
"No,never. / Yes sometimes."
If you're ever in HK, do come and see me.
"Have you ever been to Hong Kong ?"
"No, never. / Yes, I have."

He rarely, if ever(=probably never) comes to HK. He is in Singapore.
It is used after how, what, where, who, why, and Have for giving force to a question.
eg:-Have you ever been to Hong Kong ?(as a question form.)

一般來說, past perfect tense 會用於描述兩個過去的動作，而其中一個已經徹底完成了。