I already did not doubt of the existence of “book of the dead god” but…
Interestingly, depending on the context, translating 既に by “too late” could work (at least, I guess so) but would imply something completely different. I haven’t read the manga but I have seen the anime and this alternative translation may have been said by L when he realised the existence the death note really exists but he did it too late.
毎朝仕事へ行くとき一時間ぐらい日本語の練習を既にしています。
Hooray, Death Note! But I like the variety of signs too, they are very practical as well. Both are fun.
I was already not doubting the reality of the Death Notebook
携帯電話を忘れっぱなし気づいた時はすでにうちに出た。
Every morning when I go to work, I’m already practicing Japanese ~1 hour.
I don’t understand why it means “reality of the Death Note”, it’s 「死神のノート」を現実だ, neither 「死神のノート」の現実だ nor「死神のノート」が現実だ. Does 現実 act here like a suru verb, that’s why?
The を feels off to me somehow or at least I don’t think I’ve ever seen 気をづいた
Yeah, it sounds off, I was wrong, thx! Update to 気づく
What were you trying to say with that? I’ve seen きをついて/た used before, but perhaps you were going for something else.
There are many つくs but most are intransitive from what I see. 気がつく may work as well here, I always assume this was the long form of 気づく. The intent was to say “realized”. I only know 気をつけて (be careful), definitely a transitive verb but not familiar with any きをついて/た.
I thought I had seen more usages, evidently not. The only thing my Anki shows as a usage would be the following sentence from WK
大きくいきをついてください
Please exhale deeply.
Maybe a pro can chime in, perhaps I’m thinking of が instead of をhere.
I don’t know if you noticed, but even in that sentence, it’s 息(いき)をつく and not 気(き)をつく. 
I should never post 5 minutes after waking up from a nap, thank you! Disregard my entire series of posts now lmao
Here’s my guess after doing a little research…
I found this page that says 〜を現実だと思う means “to regard ~ as reality”. So it seems like in this case 〜を現実だと疑う could mean “to doubt ~ as reality”?
For this one, it might be that you’re used to seeing the verb following を straight away. However, for する verbs, it might be better to think of them as nouns… Because they are nouns.
A word attached to する is never actually a verb, する itself is the verb, and in casual Japanese, you can make -any- noun into a する verb (タピをする) “To drink bubble tea”
Japanese is language in which the information before the particle is important, not after. So in this sentence, the を is not actually connected to 現実 at all, but 疑う, which is a transitive verb.
だと has a few different functions, and to be honest a few of them could work in this sentence. But for me the one that felt the most accurate was the ‘that’. In this sentence he could leave out 事実だと, but it would be far less impactful. It adds to why he wasn’t doubting it.
I already wasn’t doubting the shinigami notebook… that it’s real.
Sounds like a sub-thought that he just chose to throw in.
That/as are both equally correct, considering 事実 can act as an adverb or a noun. It would just depend on where you feel that the speaker is putting the emphasis.
Thank a lot for the explanation! It was very helpful. I had originally parsed it as 僕は既に「Ｘ」と疑う with the “死神のノートを現実だ” as X, but it seems either could be acceptable depending on how you interpret it.
These visualizations were helpful to me:
Option 1
Option 2
(created with Japanese Dependency Visualizer)
I noticed from your translation a few of us missed the verb being in the progressive form (@s1212z got it though!), it’s 疑ってなかった not 疑わなかった. “Already wasn’t doubting” sounds much better in English than “already didn’t doubt” too.
Just by looking at your flow chart, it seems like you’re the type of person that logically likes to stitch parts together, in which case I would strongly recommend this book.
ちびまる子ちゃんの文法教室
To be honest it is aimed at kids, but is one of the most detailed ‘basic’ Japanese books I’ve read for quickly finding how sentences are put together, and all the different word types as a Japanese person would see them. It may be a little tricky, but it explains every new concept that it introduces, so in that regard it’s pretty easy to follow.
Here’s an example of how it teaches exactly what you’re doing in your flow chart.
How could you tell? 
I definitely tend to over-analyze a bit (or try to apply too much logic) - probably why I struggle with speaking Japanese more than reading it.
I really like the way that books groups the clauses and connects them, it’s definitely similar to those dependency diagrams haha. Looks like a bit of a challenge as well with all of the explanations in Japanese. I will check it out!
おすすめありがとうございます!
August 28th Translation
Notes :
There was a bit of a discussion today about the reason that we saw を before 現実 rather than in another position. This has mostly to do with the function of だと in this sentence, which highlights that 現実だと is a bit of an inpromptu statement about the book, rather than strictly a part of the overall sentence. だと can actually have quite a few different meanings depending on the words that surround it, but most of the time it usually translates closest to ‘that’, or ‘as’. Sometimes both are equally as correct! This stresses the importance of the spectrum of nuance in translation, and why it is important not to get too hung up if someone translated something a little bit differently to you.
August 29th
にしても～にしても
Pre-translation note - While the verbs in this sentence are not する, they are behaving the same way as this grammar point. There is a special reason for this, and we would like you guys to have a bit of a guess! For your guesses, put a ＊before it, so we know what to check.
Hint! - Think about a few of the situations in which に is used in Japanese.
Side-note - We put チーム above TEAM here just as a reminder that a Japanese person would read this as チーム, rather than trying to pronounce the English word.
