Hi Eunhye!

Here are my answers to your questions! :)

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1. While he was hypnotized, the victims younger male brother recalled the morning his sister disappeared, and he recalled the person knocking on the door had a female voice.

1) first of all, I think 'victims' should be 'victim's'(the possessive)
-> Yes, you are correct!


2) why do we have to use 'male' here ? (I think it is redundant because 'Brothers' are obviously male)
-> We do not have to and I agree that it is redundant.


3) Is it wrong to say "While the victim's younger brother was hypnotized, he recalled the morning his sister disappeared, and he recalled the person knocking on the door had a female voice."?
It's just that when the pronoun 'he' comes at the beginning of a sentence, we don't know who it refers.

-> Although your sentence is definitely not wrong, it is common to use a unspecific pronoun like the original sentence in the beginning of the sentence and often it is not deemed confusing as long as it is clear whom the sentence is referring to in the sentence. Very common literature-style writing in fact!


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2. We asked Detective Park Joo Ho who has been investigating hypnosis for 17 years about it.

I would say
1) We asked Detective Park Joo Ho who has been investigating through hypnosis for 17 years about it.
2) We asked Detective Park Joo Ho who has been executing? using? hypnosis for 17 years about it.

Because Korean sentence  says  '최면수사를 진행' 
but investigating hypnosis sounds to me like '최면수사를 조사,연구'

-> I agree and #1 sounds better than #2 in my opinion. The word “executing” does not sound right here.



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3. Hypnosis investigation, which is using recalled memories and important clues, has been recognized.

1) Why present progressive here? (is using)
When someting happens and continues to happen, we use present tense
Since hypnosis investigation uses recalled memories and will continue to do so, I wonder if we can put 'use' here.

-> Trivial style differences in my opinion, and yes saying “uses” would be perfectly fine.


2) The Korean sentence says, "이 기억들이 중요한 증거나 단서로 쓰이는"
So I want to put 'as' here to mean '~로서' 'to be served as'
-> Hypnosis investigation, which is using recalled memories as important clues, has been recognized.

-> Yes it sounds fine to me!

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4. They used hypnosis on a suspect who was drunk and had forgotten his memory to find the tool he used in the crime
1) I'd like to know why the past perfect 'had forgotten' is used even though 'drunk' and 'forgot his memory' happned almost at the same time.
(Or, even 'drink' happens first and then forget the memory)


-> I don’t think applying the idea of 과거 vs 대과거 is going to be the best way to make sense of this. Saying “someone who had forgotten something” is just a very common way of saying the state of the person not being able to remember something.

2) I think past perfect should be used as below considering the chronological order
They used hypnosis on a suspect who was drunk and forgot his memory to find the tool he had used in the crime
->the fact he used the tool happened before he got drunk and forgot his memory
What do you say?

-> Both sentences sound fine to me and the difference is negligible in my opinion.


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Best regards,

Mason U, CMI-Korean
Business Interpretation and Translation in Korean (BIT-K) Instructor