Why isn't 大した using 大's Kun’yomi

[slinky07]

The way I understand things, usually, when there is hiragana attached to a kanji, it will use the kun’yomi. Is there a reason this word doesn’t? I am trying to understand the exception here as it keeps confusing me.

I understand I am new, and I guess there is a grammar reason to it (or not!) so I ask this question here to find the answer. sorry if it has been asked before, I tried to search before asking.

Thank you for your time!

[plantron]

Okurigana : Kun'yomi and On'yomi

Hello! I have a question about Okurigana. For exemple: 大きさ is an okurigana because it has a Kanji followed by a hiragana, so it means that I should read as “おおきさ”(Kun’yomi). However my question begins here, the word “大した” the “大” is followed by hiragana as well but instead of reading as Kun’yomi “おお” we read as On’yomi “たい”. Why tho? Thanks in advance

[slinky07]

oh, thanks, I guess I did not look hard enough! Interesting thread

[Belthazar]

Heh. I was all ready to come in here and basically re-type my exact response from that thread, but this saves time.