I found it interesting being back at school again. 關於這句句子的結構?

I found it interesting being back to school again.
主詞＋動詞＋虛受詞＋受詞補語＋延遲的受詞
主詞：I
動詞：found
虛受詞：it（形弍上的受詞）
受詞補語：interesting
延遲的受詞：being back to school again（動名詞片語）
back後面的介系詞應用to，而非at
受詞比受詞補語的文字長時，會將受詞移後，放上虛受詞it，以便閱讀及理解（尾重原則）。

It is interesting being back to school again.
這裡的it是虛主詞，主詞補語interesting後面的being back to school again則是延遲的主詞（delayed subject）。這也是尾重原則的結果。

Being=present participle of BE;
Being back to school again---------present participle phrase, adjective; qualifying the subject "I".
Hence:-eg:-All being well and interesting; I should arrive school.
----------eg:--It is interesting when I go back to school again.