YOU SAID:

the dog went o the park when he found out he had lost his new red ball at the pool next door

INTO JAPANESE

犬は隣のプールで新しい赤いボールを失ったことを知ったときに公園に行きました

BACK INTO ENGLISH

The dog went to the park when it knew that it had lost a new red ball in the next pool

INTO JAPANESE

犬は次のプールで新しい赤いボールを失ったことを知って公園に行きました

BACK INTO ENGLISH

The dog went to the park knowing that it lost a new red ball in the next pool

INTO JAPANESE

犬は次のプールで新しい赤いボールを失ったことを知って公園に行きました

BACK INTO ENGLISH

The dog went to the park knowing that it lost a new red ball in the next pool