今、教科書でIt seems that〜、It seemed that 〜を S seem(s)(ed) to 〜に書き換える項目を扱っています。
例文として、S seem(s) to do 〜 S seemed to do 〜 S seem(s) to have p.p S seemed to have p.p
を、同じ単語を使って比べたいのです。 例えば、My dog seems to understand English. My dog seemed to understand English. My dog seems to have understood English. My dog seemed to have understood English.
My dog seems to understand English.
My dog seemed to understand English.
My dog seems to have understood English.
My dog seemed to have understood English.
の違いならテツオさんの切り口でも高校生とかには
OKなのでは?
これはRaising Sentenceというものですね。
例文で用いている語が理解を妨げているようなので、変える必要があると思います。たとえば・・、
i)He seems to be rich.
ii)He seemed to be rich.
iii)He seems to have been rich.
iv)He seemed to have been rich.
いかがでしょうか。