YOU SAID:

I know this, because yesterday, I saw them flying round my living room.

INTO JAPANESE

昨日、私は彼らが私の部屋の周りを飛んでいるのを見たので、私はこれを知っています。

BACK INTO ENGLISH

I know this yesterday because I saw them flying around my room.

INTO JAPANESE

私は彼らが私の部屋の周りを飛んでいるのを見たので私は昨日知っている。

BACK INTO ENGLISH

I know yesterday because I saw them flying around my room.

INTO JAPANESE

私は彼らが私の部屋の周りを飛んでいるのを見たので昨日知っています。

BACK INTO ENGLISH

I know yesterday because they saw them flying around my room.

INTO JAPANESE

彼らは私の部屋の周りを飛んでいるのを見たので彼らは昨日知っている。

BACK INTO ENGLISH

They knew yesterday as they saw flying around my room.

INTO JAPANESE

彼らは私の部屋の周りを飛んでいるのを見たので彼らは昨日知っていた。

BACK INTO ENGLISH

They knew yesterday as they saw flying around my room.