ある (aru) Japanese meaning: a certain | Kotomoraた
。
One day, I suddenly got a call from him.
In a certain sense, what he says is also correct.
Usage patterns
ある日one day (used to open an anecdote or story)
One day, he suddenly called me.
あるときat a certain time; once
At one point, he suddenly said he was going to quit his job.
ある意味でin a sense; in a way
What he says is, in a sense, correct.