YOU SAID:

i ran across the world to swim in my friends pool.

INTO JAPANESE

私は友達のプールで泳ぐために世界中を走りました。

BACK INTO ENGLISH

I ran around the world to swim in my friend's pool.

INTO JAPANESE

私は友達のプールで泳ぐために世界中を走り回った。

BACK INTO ENGLISH

I ran around the world to swim in my friend's pool.