YOU SAID:
My son did not catch the catch
INTO JAPANESE
息子は釣れなかった
BACK INTO ENGLISH
My son couldn't catch
INTO JAPANESE
私の息子はキャッチできませんでした
BACK INTO ENGLISH
My son could not catch
INTO JAPANESE
私の息子はキャッチできませんでした
BACK INTO ENGLISH
My son could not catch
That didn't even make that much sense in English.