YOU SAID:

my younger brother decided to go fishing in the early spring

INTO JAPANESE

早春の釣りに行くことを決めた私の弟

BACK INTO ENGLISH

In the early spring decided to go fishing with my brother

INTO JAPANESE

春先に私の兄と一緒に釣りに行くことを決めた

BACK INTO ENGLISH

Decided to go fishing with my brother in early spring

INTO JAPANESE

春先に私の兄と一緒に釣りに行くことを決めた

BACK INTO ENGLISH

Decided to go fishing with my brother in early spring