Function of だと and と in this sentence: 興味のある事だと、あなたは一生懸命に理解しようと努めるでしょう。

Question

興味のある内容で学習しましょう this is the title of original text where I pick up the sentence to give better understanding of what is said.

The sentence is:

興味のある事だと、あなたは一生懸命に理解しようと努めるでしょう。

I know that と can mean "and", "with", "when A happens B also happens". What do だと and と mean in this sentence?

Answer 1

The first だと is actually two words, だ ("is", the copula) and a conditional-と. That is, ～だと means "if [something] is ～...". See Differences among -たら, なら, -と, -んだったら, -ば, etc and How Conditionals Work in Japanese: …と, …ば, …たら, and …なら.

The first half of the sentence can be broken down like this:

• 興味がある
  to be interested (more literally, "you have an interest" or "there is an interest")
• 興味のある事
  something you are interested in
  _{(a relative clause with ga-no conversion)}
• 興味のある事だ
  (That) is something you are interested in.
• 興味のある事だと、...
  If that is something you are interested in, ...

---

The second と is part of the ～ようと(する) construction, which means "to try to ～". See Volitional + と + Verb and What is the difference between "verb＋て＋みる" and "verb＋(よ)う+とする"?. (と by itself is a marker for the content of an action, but you have to memorize -ようと as a set phrase first.) Thus the last half of the sentence means:

• ...あなたは一生懸命に理解しようと努めるでしょう。
  ...you will strive hard trying to understand it.
  ...you will strive hard in order to understand it.