expression
for that very reason; that is exactly why
Emphasizes that a preceding statement is the precise reason for the following result. Often used in formal or literary contexts.
彼は努力を惜しまなかった。さればこそ成功したのだ。
He spared no effort. That is exactly why he succeeded.
expression
as expected; just as one thought; sure enough
Used when a result confirms what was previously thought or predicted. Slightly old-fashioned; modern Japanese often uses やはり or 思った通り.
As the forecast said, it started raining in the afternoon. Just as I thought, I brought an umbrella.