It 文

It is important to study every day.
It’s my job to make sure to check everything is ok.

It is important for him to study every day.
toVの意味上の主語

It is kind of you to say so.
この場合　意味上の主語などはあなりない　of  to  これは相手をもともと限定しているあなたの一部（やさしさ）
It is nice of you to come all this way to see me.   はるばるありがと会いにきてくれて

It is strange that she is so quitet. 彼女あんなに静かで不思議。
これは　that 接続な感じ　

It is 形容詞　wh系 も　接続系　
It is not important who did it.    など

It seems that he is tired.    も　『ようだ、らしい、・・・と思われる』
自分の視点をいれたければ
It seems to me everything is going well.   など　to me など

It takes  It cost  svoo 　svo toVなどでよく使われる

It said that he is one of the most succussful businessmen in rh world.

It 文　質問の答えに

it文が　名詞節になって

I think It is important for him to study every day.

It was careless of him to forget to lock the door.
それは彼の不注意だった　→　forget
ドアの鍵を忘れるとは彼の不注意だった。