というのは

expression, conjunction

because; the reason is

Used to explain a reason or cause, often at the beginning of a sentence or clause. Equivalent to 'the reason is that...' or 'because...'.

• 彼かれは遅ち刻こくした。というのは、電でん車しゃが遅おくれたからだ。

  He was late. The reason is that the train was delayed.

• 今日きょうは休やすみます。というのは、熱ねつがあるんです。

  I'll take the day off. That's because I have a fever.

expression, conjunction

as for; regarding; when it comes to

Introduces a topic or subject, similar to 'speaking of...' or 'as for...'. Often used to clarify or ask about something previously mentioned.

• というのは、昨日きのうの話はなしのことですか。

  Are you talking about what we discussed yesterday?

• 彼かの女じょはとても親しん切せつだ。というのは