since it's... (knowing how they are)

ことだから bases a prediction on the known character of a person. Attach it to a noun with の, usually a person. The speaker reasons that, given what that person is always like, a certain outcome is expected.

Examples

• 彼かれのことだから、また遅おくれてくるだろう。

  Kare no koto dakara, mata okurete kuru darou.

  Knowing him, he'll probably be late again.

• 真面目まじめな田中たなかさんのことだから、必かならず来くる。

  Majime na Tanaka-san no koto dakara, kanarazu kuru.

  Since it's the diligent Tanaka, he'll definitely come.

Vocabulary in these examples

• 彼 he, him
• また again
• 遅れる to be late
• 真面目 serious, diligent
• 必ず certainly, without fail
• 来る to come

Related patterns · Cause and reason

• 〜だけに precisely because; being... all the more
• 〜ばかりに just because (with a bad result)
• 〜ものだから because; the reason is that (excuse)
• 〜あまり out of too much; so... that