YOU SAID:

i guess i'll go to mcdonalds with my sister

INTO JAPANESE

私は妹とマクドナルドに行こうと思います

BACK INTO ENGLISH

I think I'll go to McDonald's with my sister

INTO JAPANESE

私は私の妹と一緒にマクドナルドに行こうと思う

BACK INTO ENGLISH

I think I will go to McDonald's with my sister

INTO JAPANESE

私は私の妹と一緒にマクドナルドに行こうと思う

BACK INTO ENGLISH

I think I will go to McDonald's with my sister