Cause & Reason: おかげで vs せいで vs ばかりに vs ことから vs ことだから
Japanese encodes into the grammar itself what English leaves to tone: whether the outcome was good or bad, whether the cause was trivial, and whether you are inferring from evidence or from knowing someone's character.
The patterns
おかげで
thanks to (good outcome)
先生のおかげで合格できた。
Thanks to my teacher, I passed.
せいで
because of (bad outcome, blaming)
渋滞のせいで遅刻した。
I was late because of the traffic jam.
ばかりに
simply because ~ (one small thing caused disproportionate harm)
一言余計なことを言ったばかりに、喧嘩になった。
Just because I said one thing too many, we ended up fighting.
ことから
from the fact that (objective inference)
服が濡れていることから、雨に降られたとわかった。
From the fact that his clothes were wet, I knew he had been caught in the rain.
ことだから
knowing ~ (judgement based on someone's known character)
彼のことだから、また遅刻するだろう。
Knowing him, he'll be late again.
だけに
precisely because ~ (all the more so)
期待していただけに、がっかりした。
Precisely because I had hoped for it, I was all the more disappointed.
からこそ
it is exactly because ~ (and no other reason)
あなただからこそ、これを頼むんです。
It's precisely because it's you that I'm asking this.
Decision procedure
Is the outcome good or bad?
Is it "one tiny thing caused an outsized disaster"?
Inferring from objective evidence, or from knowing the person?
Emphasising background that intensifies the result, or exclusivity of the cause?
Commonly confused
だけに vs からこそ
だけに works with good *or* bad results and can even mark an ironic reversal. からこそ has a hard restriction: it is essentially limited to positive results. That asymmetry is the reliable test.
ばかりに vs せいで
Both mark bad outcomes, but ばかりに stresses that one small act caused damage out of all proportion. せいで simply assigns blame with no "small cause, big effect" nuance.
ことから vs ことだから
ことから infers from an objective clue ("his clothes are wet, therefore…"). ことだから infers from a person's known track record and almost always attaches to a person with の.